You Be the Jury: Survey on a Current Event

On a cursory reading of Wikipedia the obvious interpretation is that Knox and Sollecito are innocent and Guede is guilty. I didn't go through all the sites so I don't know if this would qualify as a litmus test, and assigning probabilities in this state of knowledge would be extra work.

EDIT: Read comments and am surprised at how many estimates of "Knox and Sollecito probably didn't do it" have probabilities in the range of 40% attached that they did. If it were a binary judgment or a confidence interval, then yes we should avoid extreme probabilities and widen intervals to compensate for known overconfidence biases. But in this case the hypothesis space of equally plausible possibilities is large, and some low-probability symbols were used to write the message (multi-person rape-murder vs. single-person rape-murder, female rape-murder vs. male rape-murder). It may not always be easy to unravel crime scenes (though this one sounds pretty straightforward) but to focus on Knox or Sollecito seems like privileging the hypothesis.

Unless there's major prosecutorial evidence not in Wikipedia, then this seems like a case of paying too much attention to other people's opinions (the jury, in a case where we have further information that the verdict gained media attention as possibly inaccurate), and I would suggest that anyone who gave a probability higher than .15 be more arrogant in the future.

If, of course, I just haven't done enough reading, then ignore the above.

I began with zero familiarity with the case.

1. Knox: 8%
2. Sollecito: 10%
3. Guede: 95%
4. Agree with komponisto: 80%

Rationale for considering Sollecito more likely than Knox: They're linked quite closely here, but there's enough confusion surrounding the case that I can't take that completely for granted. That being the case, it's unlikely-but-possible that one of Knox or Sollecito was directly involved while the other wasn't, and my prior for a male committing a violent rape/murder is a lot higher than for a female.

Guede is clearly guilty. He fled town immediately after the murder. His DNA was found in the victim's body, by far the most difficult-to-contaminate piece of DNA evidence in the case, making it extremely likely he's the rapist. Very low prior on a rape/murder being committed by separate parties.

The inconsistencies in Knox and Sollecito's stories are definitely worth paying attention to. But there are several factors diluting their importance:

• I already had a reasonably high prior on the prevalence of brutality and corruption in Italian police forces. This doesn't leave me with much faith in their competence, especially when it comes to interrogations.
• It's known that Knox and Sollecito were intoxicated with alcohol and marijuana at the time. I don't know how many of you have ever been thoroughly trashed on this duo (I'm guessing the number is disproportionately low here), but memories formed under such circumstances are very fragile. I've personally experienced disagreements provoked by divergent recollections of events that had transpired an hour previously. Given that sort of influence, I know I would have a damn hard time reconstructing a coherent narrative of the night's events after the brutal murder of my roommate and several days of interrogation by Italian police.

The DNA evidence against Knox and Sollecito is also worth paying attention to, and is in fact the primary reason my estimate on their guilt is as high as it is. However, this is partially mitigated by a glaring problem with the case: Most of the evidence was collected before Guede was a suspect. If Guede had been identified from the start, the Knox-Sollecito hypothesis may not have been quite so "privileged". IIRC, the DNA of four unidentified individuals was also found on the knife. Plus the doubt wrt the knife matching the wounds. Plus the odds that Sollecito would take a murder weapon back to his apartment and put it away. My generally unfavorable prior wrt Italy's justice system also adds a fair amount of room for uncertainty here.

The fact that Guede wasn't initially identified also provides the police with a mild motive for contaminating the evidence. It's unlikely that such an action would be detected. That said, my prior for this sort of action is pretty low.

Finally, we come to the elephant in the case: The hypothesis that the murder was committed by three people working together, as the result of a sex game gone bad. This reads like a parody of a flailing prosecutor. Contrast prior with that for a "normal" rape/murder... ouch. And it just so happens that the one party implicated by actual, solid evidence is the one party who fled after the crime.

The rationale for my 80% chance of agreement with komponisto is mostly based on "metagaming" his position. He admits to having a "rather strong" opinion on the case, and it seems much, much harder to form a strong opinion in favor of guilt as opposed to innocence in this case. My estimate would be higher, but given how asymmetrical this case appears to me, I can't rule out "initial counterintuitiveness" and/or extra evidence as a possible motivation for posting this in the first place.

I'll read the other comments and post my update later today.

What is completely sad (besides this horrible murder case), is the inability of either website linked to present a coherent, rational argument. In fact, I haven't been able to find one website that reveals all facts and then explains them with their point of view in a rational (or even semi-rational) way.

I find this situation almost as depressing as the murder. I couldn't come to any conclusion based on the poor quality of reasoning used on most websites. Wikipedia, as usual, presents a decent collection of facts.

From the Wikipedia article I could only ascertain that Rudy Guede is very likely guilty. My probabilities for the other two being guilty are low (but have a lot of uncertainty), certainly not enough for me to feel that the verdict is correct.

Perhaps this is after all a litmus test for rationality, in a different sense than (I suspect) komponisto intended.

I mean, here I am looking at a 100+ comments thread, discussing a highly charged issue, and everyone is thoughtful, respectful, and willing to take others' points into account.

That is... extremely unusual.

Having lived for 14 years in Italy, my impression is that several commenters severely overestimate the rationality and fairness of the italian police force.

5% for the couple, 99% for the first convict. 90% that my probability estimate is close to yours in the sense that you think the two are innocent and the one is guilty.

I'd read a bit about this in the news, and I checked out those sites and wikipedia.

Given the fact that there is no evidence of prior acquaintance of the couple and the man, combined with the fact that the man did not attempt to implicate the couple despite the overwhelming evidence against him, make it very unlikely that they were involved. That, and one person being crazy/desperate/disturbed enough to commit a brutal rape-homicide is much, much more likely than one person and a completely unrelated couple he's never met before being disturbed enough to commit a rape homicide. The defense's response to forensic evidence appeared pretty strong, and the pro-guilt group did not seem like they tried to seriously rebut this (they mentioned that one defendan't DNA was on the bra strap, but failed to mention three other unidentified people's DNA on it as well).

The fact that the prosecutor is under investigation for previously using crazy psychotic hypersexual homicidal maniac theories without basis does a lot to explain how the prosecutors ended up with such a crazy theory.

My estimate of your position was (as I perceived it) largely independent of my own analysis. You mention a number of confounding factors as to why people are likely to be wrong about these things, with no mention of why they might be right, and you posted this in response to their conviction. It would be very surprising to choose a decision you agree with as an example of problems with human rationality.

I was unfamiliar with the case. I came up with: 1 - 20% 2 - 20% 3 - 96% 4 - probably in the same direction, but no idea how confident you were.

From reading other comments, it seems like I put a different interpretation on the numbers than most people. Mine were based on times in the past that I've formed an opinion from secondhand sources (blogs etc.) on a controversial issue like this, and then later reversed that opinion after learning many more facts.

Thus, about 1 time in 5 when I'm convinced by a similar story of how some innocent person was falsely convicted, then later get more facts, I change my mind about their innocence. Hence the 20%.

I don't think it's correct to put any evidential weight on the jury's ruling. Conditioning on the simple fact that thier ruling is controversial screens off most of its value.

priors

Amanda Knox is guilty: 75%, Raffaele Sollecito: 75%, Rudy Guede: 25%. I shall abbreviate future percentage triples as 75/75/25.

No knowledge of the case before reading this post. My prior is due to my assumption that trial people know what they are doing, and on the fact that I imagined that the trial was trying to show that the guilty were K+S instead of G.

acquiring information

Reading about G's DNA, which should be rather good evidence: switching to 50/50/75. I contemplated switching all the way to 25/25/75, but I figured there had to be some reason for the new trial.

Reading about the police's claim that the murder was linked to a group sex game; thinking that this would be a ridiculous motive. This made me think that maybe the trial people didn't knew what they were doing after all. Switching to 25/25/80.

Finally realized that the trial was in fact trying to show that the guilty were K+S+G instead of just G, not K+S instead of G. Stopped keeping track of percentages for some reason.

Reading about the police switching from K+S+L to K+S+G, which lowered my esteem of the police even more.

Reading about the DNA of K+S, figured it was natural for a woman and her boyfriend to have DNA all over the woman's own house.

Still trying to understand who was G relative to the others. I think he's a robber now. Definitely not part of the group sex thing. Even worse feelings toward the police.

Over all, the truejustice website seems more emotional than the friends of K website, which surprises me. I would have expected the family of the victim to have calmed down after the original G trial, yet truejustice still seemed angry; and doesn't even seem to be ran by the victim's family at all. They should be a lot less emotional about this than K's friend, which seem to be a lot more clearheaded than truejustice is.

I'm now quite convinced of the innocence of K+S, although I'm too shy to give an actual percentage. 5/5/95, if not more extreme.

Familiarity pretty good - I've read the Wiki page, revisited several articles from when the murder was first discovered and I watched Sky news the day of the verdict and saw/heard Prof of Criminology, feminist journalist, UK barrister and two Italian barristers. I frequently search the web, hence I found this site.

(I don't understand the up/down system.)

I find the logic of the murder disturbing - if the murder was a game gone wrong, then it was not premeditated, so unlikely gloves were worn. If bleach was used to clean, then why was Guede's DNA all over the body and room? The only DNA evidence for Raffaelle is highly suspect and a physical impossibility to leave DNA only in that one place I would think. That really is the beginning and the end of it.

The Prof of Criminology's view I have to take seriously. But, in saying that Amanda's diary reads like a gap-year Rosemary West he failed to draw contrasts as well as comparisons. Rosemary West was severely abused from early chidlhood, she did not study languages or develop an interest in creative writing.

I have an alternative scenario - a young woman from a comfortable secure All-American upbringing, who has no idea of the level of corruption and politicking in the world, visits Italy and discovers the magic of old Europe and the unexpected appeal of herself to Italian men - the intoxicating culture of Italy, the constant calls of 'Ciao Bella' from men lounging in doorways - and, being naive and unwordly, behaves carelessly and without circumspection not realising that beneath the relaxed veneer of Italian culture lies a strict code of conduct, especially for women. Amanda has behaved exactly as you would expect of an innocent girl with that background - she simply could not comprehend that she could be convicted for a crime that she did not commit and didn't take her interview with the police seriously.

Given the above scenario, when asked to imagine what might have happened that night, Amanda may well have enjoyed being able to apply her obvious interest in macarbre story telling. I myself wonder at the violence depicted in much fiction but being able to express the human condition in fiction is important and we should not rush to criminalise the use of the macarbre in fiction.

I don't want to cast aspersions but I found it very strange that Meredith's parents did not talk at the press conference and I started to find their silence spooky rather than dignified. I also think that Meredith had made it clear to her family that she did not at all like her flatmate's arrogant American 'no one can touch me' attitude. Supposing the Italian barrister dangled the potential for millions in compensation in front of them? How would they feel?

And why does Meredith's mother now say that querying the verdict is making her unhappy? Would she not care if an innocent went to jail? And surely the pain of her daughter's death is not going to disappear from her mind even when the story disappears from the media? It starts to sound more like a desire for revenge than for justice.

Finally, I've worked with about a dozen Italian professionals and was astounded by their anti-American feeling. There have been US bases in Italy since WWII and Italy led the anti-Iraq war movement with their colourful Pace flags.

I don't know what Amanda and Raffaelle were up to that night. I think they were in the first bloom of attraction to each other, on drugs (perhaps more than just cannabis), and not being particularly sensible. But the case is not beyond reasonable doubt, neither is accusing the other, and they have served 2 years in jail already.

PS. this site is a very welcome find - it seems that many, many people these days prefer 'opinion' to logic or standards - I call it the Strictly Syndrome - a cult of personality combined with sectarian affiliations - it's really quite scary to hear how little people care about evidence, universal standards or intelligent debate nowadays. Bring back the Enlightenment, I've had enough of postmodernism!

I averaged up the answers given so far in this thread for Knox and got 35% mean, 20% median.

I arrived at the site from the HP fanfiction after reading the author's notes concerning the case.

Probability estimate that Amanda Knox is guilty -- 99%

Knox and Sollecito's alibis are contingent on the other. However, I recognize that there is a probability that one may lie to cover the other, so it is not implausible that one may be guilty without the other being so. While they certainly had the opportunity to murder, there appears to be neither motive nor weapon. The only credible evidence against Sollecito is his DNA being on the bra hook material, and there's a great deal of controversy regarding that specimen. The knife thing is just stupid. I have had roommates, and I can guarantee you there are DNA traces of both me and my roommate on pretty much every knife we've ever had. Frankly, the only reason I'm judging Knox's probability of being a murderer being so high is that they're two girls who shared a bathroom, so she automatically has motive.

I recognize that having read the author's notes, I am biased to believe that Amanda Knox is innocent. That being said, I am completely unfamiliar with the case. I went to the pro-guilty site first, where I had a great deal of difficulty discerning relevant information. I spent approximately 20 minutes navigating the site, growing more and more convinced that Amanda Knox and Rafaele Solecito were not guilty because of the near-impossibility of finding relevant facts that pointed out to their guilt. I then went to the pro-innocent site, and spent about 5 minutes there, which confirmed what I suspected; that the evidence against said defendants was completely circumstantial. I then proceeded to read approximately 1/2 of the Massei report, which struck me as rather biased, which made me very sad when I realized he was the presiding judge in the case. Regardless, by that point I was convinced the prosecution had no case, and was largely built on inconsistencies in Amanda Knox's testimony. I was then annoyed to realize that much of the case had to do with Pretty White Girl Syndrome, because however little evidence there was against Amanda Knox, there was even less against her boyfriend Sollecito. I the proceeded to the Wikipedia article, because let's face it, there's really no better place for an overview of the whole shebang . At this point, I'm pretty much offended at this travesty of justice. The evidence against these two defendants seems to be, "they did not have completely time-consistent alibis" and some bum says he saw them together near the murder scene.

edit: I am basing my probabilities on two primary factors: 1) I saw no evidence that Knox or Sollecito were at the crime scene and their alibi seems eminently plausible to me and 2) The pro-guilty site seems batshit crazy.

Page one of the site arguing defendants are guilty has nothing that would count as evidence for guilt. When I got to the bottom of the page and saw that there were 24 more pages, I lost patience for the exercise because the low quality of the argumentation on page one (most saliently, the picture of the vicitim when she was five, which if course is not evidence at all, but which will tend to evoke biased thinking in the reader) was a sign that the other 24 pages would be very sparse in actual evidence.

Aren't there enough opportunities for us to practice rationality such that we can check our answers to make it mostly a waste of time to assign probabilities to an event for which it will probably forever be impossible to know "the answer"?

Your job will be to browse around these sites to learn info about the case, as much as you need to in order to arrive at a judgment. The order, manner, and quantity of browsing will be left up to you

If you are going to leave it up to the reader, you should at least tell us where on the 25 pages the strongest evidence is on the site arguing defendants are guilty.

Never heard of the case before, after reading the wikipedia page on the crime and its associated discussion page I think it's very unlikely that knox and sollecito are guilty. Certainly the evidence does not seem at all sufficient to convict them, and interrogating someone for 14 to 30 hours without recording the interrogation is downright idiotic.

I expect you agree.

I'd like to see more posts of this nature. This site has too much theory and not enough practice.

I guess we were all guilty, in a way. We all shot him, we all skinned him, and we all got a complimentary bumper sticker that said "I helped skin Bob".

my somewhat admittedly sketchy reasoning:

I go to the University of Washington where there is considerable interest in the case. Of the people who have only been marginally involved in the case, most believe that Amanda Knox is innocent. Of the people who are interested in the case, many believe she is guilty. There's an obvious hometown effect here which biases towards innocence so I'm assuming those who look into the case are taking that into account when and still reach a guilty verdict.

Therefore, I assign a 70% probability to Amanda Knox being guilty (+ or - 30%).

• P(AK=guilty) = .01
• P(RS=guilty) = .01
• P(RG=guilty) = .995

Do I think my assessment will coincide with yours? Of course I do, we're supposed to be rationalists!

I had zero familiarity with the case before reading the links provided, and did not read any of the comments in reaching my estimate.

I admit to having non-trivially updated based on my perception of the lack of seriousness of the pro-conviction site's domain name (what is this, Marvel Comics?)

1.False

1. False
2. True
3. True

Why am I giving (most of) these in boolean terms rather than probabilities? Bayesian probabilities aren't useful in cases where the most probable scenario for (AK guilty) is something like "Two of the perpetrators were secretly ninjas". There really is no rational way to convict someone for leaving no forensic evidence in a room whatsoever.

I have to admit here though that I peeked at your article before posting this. And incidentally, predicted what it would say pretty damn well. (AK not guilty with a probability that reduces to 0, with the other two probabilities also expressible in boolean terms, and on the whole contradictory of the opinion of the jury)

I also have to admit I skipped straight to Wikipedia after reading your article, and found mostly that the facts you gave were correct and thus your argument was sound. My prior probability for any of them being guilty was very low however; around 10%ish. Jury decisions are pretty worthless before an appeal.

Would anyone actually be up for discussing the specifics of the case? (I don't know why but I find myself oddly interested in this case.)

As far as I can tell, the biggest pro-defendant evidence is that there is no major DNA evidence of Sollecito and Knox in the room where murder took place. We are told that there is a bra clasp with Sollecito's DNA and a knife that has both Amanda's and Kercher's DNA - both of these DNA traces are 'weak' in the sense that they are not that obvious, require a hefty search and are hard to see in lab. On the other hand, there are 'strong' traces of Guede's DNA in the victim's blood and in the room.

So, the first thing that worries me is that if it were a crime committed by three people, why would you have one person's DNA everywhere in the room and yet two others' only faintly there?

Again, this is the strongest pro-innocent (for Knox and Sollecito) argument that I have - and the one that convinces me most likely that Sollecito and Knox haven't done it.

I don't know - can anyone else site cases in which there was a group murder and yet only a single person left behind 'strong' traces of DNA? Maybe this isn't so unusual after all.

On the pro-guilty side, I must admit that I find Knox's and Sollecito's behavior the morning after the murder and during the investigation a bit strange. If 'Meredith was [her] friend', as Amanda Knox says in her trial, why were she doing cart-wheels during the investigation the morning after the murder? Shouldn't she be distraught and upset like all of other Meredith Kercher's friends? Accuse me of the mind projection fallacy but I feel like I would be distraught (and in a bad mood) even if the victim wasn't someone I knew.

But again, strange behavior isn't really an evidence. It's just something that makes one suspicious and raises uncertainty.

I can't find that many pro-guilty arguments. There are some tidbits that have a lot of uncertainty in them: i.e. Sollecito (allegedly) bought cleaning supplies the night of the murder allegedly again to clean up the murder mess, Sollecito claimed to be using the Internet at the time of the murder but his ISP records indicate otherwise, a woman claims to have heard three people running down that street that night.. etc. None of them as strong to make a case.

Besides these, a few other thoughts:

I really don't know how Sollecito and Knox got linked to this murder. How did they get dragged into this in the first place? Is there really evidence for the fact that it was a satanic sex-orgy gone wrong as the prosecutor claims it is? I mean, this satanic sex-orgy idea seems to be the prosecutor's imagination - there is no evidence for it.

Also, supposing Guede did it alone, would there be additional penalty or a reduction in penalty for him if he were to simply confess?

This whole thing seems to be like a backlash of conservative Italians' against whom they deem the immoral, selfish and arrogant youth. I have a hunch that the Italian prosecutor wants to punish Sollecito and Knox for a lifestyle he considers wrong.

I don't know what anyone else feels but the uncertainty of the case is somewhat disturbing. I wish there was a knockdown evidence and I could know the truth and be done with it instead of this restless search. Any else feeling that way?

1. Knox guilt: 80%
2. Sollecito guilt: 80%
3. Guede guilt: 99%

4. prob of agreement: 0.8

5. I was unfamiliar with the case before hearing about the verdicts on the news. I spent about 10 minutes on the Wikipedia article, then20 minutes on each of the sites you linked, and made these judgments before reading others' comments.

Guede's guilt seems almost beyond doubt, given the DNA evidence, his implausible story, and his flight without calling police. Regarding Knox & Sollecito, I'm convinced of the prosecution's version of events mainly by the cell-phone record evidence and the many conflicting statements given by Knox and Sollecito over time, with variation that goes beyond my (only moderately informed) expectations for bad memory or coercive interrogation.

Meta-evidence judgments: in the pro-guilt site you linked, it took a while to find concrete info, but when I found the Prosecution's case->Facts Presented section, I found a lot of very specific detail regarding the exact times cell phones were turned on and off and the times and durations of calls made, as well as detail regarding the forensic evidence and the credentials of the experts who testified about it. The pro-innocent site lacked such specifics and didn't seem to account for all the damning details. Both sites seemed very distorted by affection for Kercher (pro-guilt) and Knox (pro-innocence) and their nationalities.

I read the pro-guilt site before the pro-innocent site, and I noticed this causing bias: as I read the pro-innocence site, I felt myself internally "rooting" against them, expecting that they couldn't answer all the evidence and (maybe not surprising) finding that this was so. I tried to adjust for this in my judgments.

I have a low prior for this mix of murderers committing the crime together, and a high prior for a guilty verdict given by a jury, and feel like these two facts approximately cancel out.

After reading others' comments, I was surprised that most others leaned toward Knox's and Sollecito's innocence. I would update my judgments only marginally because of this, because I read the linked sites more closely than others' claimed to. I do however revise my estimate of agreement with komponisto down a bit to 0.6.

p.s. This is a very interesting exercise, which led me to register and comment for the first time after lurking for several months. I am very curious about your (komponisto's) judgment and reasoning.

No prior familiarity; thus I started with no information and no particular beliefs about their guilt or innocence either way.

The first thing I saw was that Ann Coulter is convinced that Amanda and Raffaele are guilty. I immediately moved my belief in their guilt way down. When Ann Coulter takes a strong position on a controversial issue, she is almost always wrong.

From there it was mostly downhill for the prosecution, as far as I could tell.

"Later, when a airtight alibi forced the authorities to release Lumumba, they substituted Guede as the third participant in the alleged sex game, even though he had no known connection to either Amanda or Raffaele." That's just stupid. I don't trust the Italian police, or any police, when it comes to high-profile cases. The political pressure to get a guilty verdict is strong. Then, clear evidence that their original theory of the case was wrong came in, and they didn't significantly revise the theory. Not good.

The pro-guilt side keeps promising links to the "evidence," but I'm not finding it. Very irritating.

I don't care at all that their statements were confused. "She was kept up all night, claims to have been hit, and was denied a lawyer and professional translator" -- or so says the pro-innocence site. Sounds like standard operating procedure when you want to get someone convicted, regardless of the truth.

The physical evidence is confusing. I would need to know a lot more about DNA and luminol and so on to evaluate the claims and counter-claims here.

Total time spent, 45 minutes. My conclusion is maybe 10% guilty for these two, but it's a very tentative conclusion and I know that much of it is based on my belief in Ann Coulter's wrongness ... which is the sort of appeal that shouldn't be reliable -- although based on experience it appears to be.

Amanda Knox guilty: .01

Raffaele Sollecito guilty: .01

Rudy Guede guilty: .99

I've become highly familiar with this case since the verdict came down. Over the last 2 years, I've heard bits and pieces about it and all along had assumed Amanda and Raffaele were guilty. I'm a little embarrassed to admit how much time I've spent reading up on the case recently - I think I'm motivated to learn more because I'm perfectly appalled at the amount of misogyny (not necessarily anti-Americanism) I see from the prosecution and the European media with regards to Amanda Knox. I'm also appalled at how much rumor is reported as fact.

I consider myself to be highly familiar with both sides' arguments, but did as you suggested and also spent some time looking over both sites you recommended - my opinion did not change.

I'm pretty confident our opinions are shared.

Looking forward to your thoughts on this experiment of yours.

For Knox, Sollecito, and Guede in order: 30, 30, 95, but didn't find either website or Wikipedia enough to feel like I had sufficient information. I think you probably thought the same.

EDIT: After looking at everyone's comments, I'm revisiting to 20, 20, 95. Anyone else want to edit their comments to say how they updated in light of everyone else's opinions?

I was unfamiliar with the case. After checking out both links for quite some time, but prior to reading the comments, I estimated:

1. 80% (Knox)
2. 60% (Sollecito)
3. 95% (Guede)
4. 90% (confidence in coincidence)

After reading the comments, I was a little surprised that the consensus seems to be decidedly against Knox's guilt. The simplest explanation is that I'm just not a very good rationalist, but I don't find that very satisfying. The four parts of the story that I felt were inconsistent with Knox being innocent were:

1. Knox's initial account of the night. I tend to believe confessions; it's a weakness of mine. With the exception of the wrong black man being implicated, I think the major thrust of it was true. Complete innocence would mean that the entire account was made up, which seems hard to believe, even if under heavy police questioning.
2. The bra was removed after Kercher's death. Would Guede have done that? I think that evidence is much more consistent with someone cleaning up after the fact.
3. The body was covered. This is inconsistent with the actions of a rapist/murderer, but very much what you would expect of someone who had a close relationship with the deceased.
4. Knox did not flush the toilet. She says that she noticed that the toilet contained a deposit, yet she walked away without flushing. Why?

I'm not sure what role Knox had in Kurcher's murder, but I feel very confident that she (and likely, but not necessarily, Sollecito) knew about the murder long before the police were called, and moved to cover it up. I can't see that as anything other than a sign of guilt, unless my understanding of the evidence itself is wrong (which is certainly possible). I can understand if some feel the need for the motive to make sense to find in favor of guilt, but according to Knox's initial account, she was stoned at the time -- which lowers my personal threshold for the expectation of rational action.

This was my first contact with this story. I still don't feel informed.

Wikipedia was the best of the resources. The site arguing defendants are guilty was the worst. My probabilities on Konx and Sollecito are "high" because I feel I still have not found an argument against them that was properly constructed. Before lowering my probability to 1% I would like to hear a better explanation of why the court found them guilty.

1. Your probability estimate that Amanda Knox is guilty. p = 6%
2. Your probability estimate that Raffaele Sollecito is guilty. p= 6%
3. Your probability estimate that Rudy Guede is guilty. p = 70%
4. How much you think your opinion will turn out to coincide with mine. p = 90% (That we both agree in direction; that RG is probably guilty. I expect your probabilities are higher though)

** Note that I leave plenty of probability for the possibility that none of the three are guilty.

Just skimmed the two sites. First:

1. Your probability estimate that Amanda Knox is guilty.
2. Your probability estimate that Raffaele Sollecito is guilty.
3. Your probability estimate that Rudy Guede is guilty.
4. How much you think your opinion will turn out to coincide with mine

1. p = .45
2. p = .45
3. p = .60
4. We probably agree on which side of .5 these numbers should be, i suspect you are far more confident, which is perhaps understandable if you have a better understanding of the evidence

It's hard to be very confident after skimming for 30-40min. I don't have the expertise or the time to verify many of the statements made by either side, especially DNA evidence and the like, but the prosecution looks pretty weak. The DNA evidence against the defense doesn't seem to hold up, and the fact that the defendant's stories are inconsistent over time show that they have the memory of, well, humans.

I should also mention that I probably have a bias for the defense in cases like this.

Guesstimates based on quick reading without serious analysis:

(1) Probability that Amnda Knox is guilty: 5%

(2) Probablility that Raffaele Sollecito is guilty: 10%

(3) Probability that Gudy Guede is guilty: 60%

(4) Probability that my estimates are congruent with OP's: 50% (ie random, I can't tell what his opinion is)

I'm pretty familiar with this case having read a couple of books about it and followed both of the websites listed and a few others.

I would say there is 0 chance of Knox or Sollecito being involved in the murder at all. They have no motive. The prosecution completely failed to show that they had ever participated in "sex games" together or with different partners in the past. There is no evidence of either of them at the crime scene at the time of the crime. None of their past behaviors make them likely candidates to commit this type of crime. Even the circumstantial evidence Judge Massei used to convict them is stretched and convoluted: that Knox bathed twice in 24 hours, that they turned their cell phone off together apparently before going to bed and on again together when they got up briefly early in the morning, that Sollecito didn't use his computer for a few hours. There are many many reasons besides taking part in a homicide by which these behaviors might occur. I doubt that these two people are in any way involved with the crime.

Rudy Guede I'd say 60% he's probably guilty of the murder. All the physical evidence, bloody hand print, bloody foot prints, mitochondrial DNA in the victim, in the victim's purse, belong to Rudy Guede. He was certainly at the crime scene. He certainly had some kind of interaction with Meredith Kercher that night. He has exactly the type of criminal profile that would lead him into this sort of circumstance. He is probably the murderer.

The thing that gives me pause is Guede's persistent denial that he murdered Kercher. This guy is a smash and grab burglar. He does not think ahead. He does not plan his escapes. He does not enter the crime scene thoughtfully with the idea of maximum profit. All his crimes are crimes of desperation, crudely executed. I doubt he meant to murder Meredith Kercher. He was there to rob. Rape presented itself to him as an opportunity. He attempted it. She resisted. He murdered her accidentally. With criminals of this type you would expect the perpetrator to be remorseful and confess. They nearly always do. Rudy does not. That bothers me.

If we believe Rudy, however, we enter the next realm of probability. Could Meredith Kercher be unlucky enough to be burglarized by Guede and then have a couple of other bandit murderers stop by , too? Doesn't seem likely to me. Was she MI5 or dealing drugs, herself? Did anybody check? I'm not happy with it.

I suspect you'll agree with me within 20%. There are no scientists or law enforcement officials outside of Italy that give any credence to the prosecution's analysis of this crime. As of yesterday, even the Italian government is backing away from these police and prosecutors. Knox and Sollecito will be freed on the review of the DNA analysis. Knox will be given time served on her so-called "slander" charge and they'll send her home to Washington state before her 24th birthday in July.

1. ~40%
2. ~20%
3. ~60%
4. I think with reasonably high confidence that you will be on the 'K/S are innocent, and G guilty'; perhaps 70% confidence

My sources are occasional articles in the NY Times, a few other mainstream media by way of Reddit, and 30 minutes of reading through the 2 linked sites. The blog one seemed very bad to me; I gave up reading it in disgust about halfway through the post on the telephone chronology, because I was tired of the breathless insinuations that if someone has a detailed phone-call, obviously they must remember it flawlessly hours or weeks later even despite an incredibly number of events & conversations in between, and any claim to the contrary is just a cover-up. I wasn't surprised to see the pro-Knox website mention that the one-fingerprint was not significant according to the fingerprint expert witness.

(This makes sense to me - if Knox were industriously cleaning up the entire cottage, how could she miss a glass cup? I mean, you can actually see fingerprints on glass cups, so I don't how she could very competently clean up all the hidden and obscure fingerprints that there was insinuated to exist and then have a sudden fit of utter incompetence with the dishes.)

My original opinion was roughly 50%, moving to 60% when I heard of the conviction, but if the anti-Knox's case is that bad... And I have difficulty with the explanations of why Guede would kill Knox in conjunction with 2 others.

(And now to look at what everyone else wrote!)

Great idea. I had heard the name Amanda Knox and knew that she was suspected in a murder of another exchange student in Italy. Thats it. I looked at both sites and much of the evidence. I glanced at the wikipedia page briefly and did a limited google search to try and find information about one more fact that I was hoping to find in the pro-Amanda page, but didn't.

My answers:

1. 13% she was in the room and assisted in the murder. 9% She was involved in some other way, had prior knowledge etc..

2. 15% in the room, 9% other involvement.

3. 97%

4. I'd say there is a 60% chance all your estimations are within 15 percentiles of mine.

A couple notes: The thing keeping 1 and 2 up there for me are the times on Knox's phone calls to Kercher. 3 and 4 seconds is way to short. But so much of the Kercher site appears to be unsubstantiated rumor I can't figure out if this was actually evidence or made up and unproven. I also can't figure out what Sollecito and Knox claimed to be doing during the time frame of the murder. They were obviously on drugs and then coerced into false statements so it is plausible they would be confused and have inconsistent stories but I don't know what they ended up claiming in court so I'm left with their statements to the police.

Also, I found that seeing the faces of the girls immediately undermined my objectivity. Not one way or another necessarily, but I felt emotional attachments to the case coming on at a disturbing rate. I would feel a lot better about my estimations if I hadn't seen their photos.

Finally, making this comment without seeing anyone else's estimations is definitely a little scary.

Update: I've gone over the timelines. Incredibly frustrating since I can't seem to find an objective account anywhere. But it doesn't look good for Knox and Sollecito. The short phone calls are really bothering me. I'm bumping up the probabilities they were involve by 25% each. Since I'm now in the middle I imagine I'm not that close komponisto's view. I'm gonna take a break since reading this stuff is making me really sick. But does anyone have an explanation for the phone calls?

Amanda Knox being Guilty: 90%

Raffaele Sollecito being Guilty 90%

Rudy Guede being guilty: 90%

I hope you agree with me because no one else in the comments seem too. I'm gonna give the probability of you agreeing with me 75% based on my own arrogance and belief that I'm right and based and little else really.

Most people seem to believe Rudy Guede is guilty so lets skip that and look at the other two. They've changed their stories and have been proven to have lied quite a few times. For example Rudy at one point said he was at home surfing the internet but his alibi is not substantiated by records of his internet service provider.
Amanda at one point said she was round Rudy's house till 10am (later changing her story) but according to a witness she was at the store as soon as it opened to buy cleaning products.

That alone is some strong evidence that they are both guilty.

If they were innocent there would be no need to lie.

Probably the most damning piece of evidence is this:

When Sollecito's home was searched, a knife was found in a kitchen drawer that contained small traces of Kercher's DNA on the blade, and Knox's on the handle.

There really is no other explanation for that. Unless she was round Sollecito's home at some earlier date and cut herself on his knife.

Here's another nail in the coffin:

Sollecito's footprint was found in blood in Kercher's room.
Don't forget this was behind a locked door!

Add all that evidence to the cleaning up afterwards, the body being covered, the rape fantasies Knox had, Sollecito's DNA on her bra etc. etc. All three of them clearly killed her. The jury clearly believed so as well which strengthens my argument. They spent months examining the case, so the idea that a few minutes of internet research makes you certain they're wrong seems laughable.

1) Knox guilty = 0.2, however 0.35 that she discussed something seriously or not with Guede before the murder. 2) Sollecito = 0.05 3) Guede = .98 4) Your opinion is probably similar to mine. 5) The wikipedia article.

I was totally unfamiliar with the case. My assessment is based on ~30 minutes of reading the pro-prosecution site and ~5 minutes of reading the pro-defense site.

1. My probability estimate that Amanda Knox is guilty: 33%.
2. My probability estimate that Raffaele Sollecito is guilty: 33%.
3. My probability estimate that Rudy Guédé is guilty: 90%.
4. How much I think my opinion will turn out to coincide with yours: same direction, mine less extreme.

For me, the red flag was the way Guédé replaced Lumumba in the prosecution's theory of the crime. An investigation in which suspects are hot-swappable does not inspire confidence.

The reasoning on the pro-prosecution site did not impress, e.g., the fact that Knox did not participate in a program for exchange students at the University of Washington is taken as evidence speaking to her character, specifically, of her desire to be free of social constraints.

1. Your probability estimate that Amanda Knox is guilty.

5%. She was near the crime scene and doesn't have a coherent story about what she did that day. She might have bought bleach. Other than that they don't appear to have any evidence against her.

1. Your probability estimate that Raffaele Sollecito is guilty.

5%

1. Your probability estimate that Rudy Guede is guilty.

95%. Handprints in blood. His blood mixed with the victims. His "DNA" "inside" the victim. If he is not guilty then he was framed in a quite advanced manner. And in that case I'd expect him to have something to say about how they got his blood and handprints.

1. How much you think your opinion will turn out to coincide with mine.

Probably quite similar.

Maybe this is a bit unsportsmanlike of me, but, for the question: "What probability your own opinion is accurate", my answer would be.... low enough to preclude me from participating in the other predictions.

Very little familiarity prior to this post, read both sites for maybe 5 minutes each.

1. 50%
2. 40%
3. 90%
4. Your username looks vaguely Italian, so I'm guessing that your estimates of the chances that Knox and Sollecito are guilty is significantly higher.

I have a different objection to the premise: the presumption of innocence in modern legal systems means that the job of the jury (and by extension the legal teams) is not just to arrive at a probability of guilt but at a certain level of confidence around that probability.

I realize that these can technically be made equivalent by endless "priors" -- i.e. a juror walks into the courtroom with a certain set of beliefs, ie probability .8 that someone on trial is guilty, .01 that a sex crime would have been committed by a female rather than a male, etc etc etc, and mentally revises them according to every input -- but in any normal intuitive sense the job of a juror is not to answer the exact questions you've presented, but to judge the strength of the prosecution's case from a skeptical viewpoint.

So when you conflate the process/outcome of the trial with an independent, rational probability estimate, I think you make it hard for anyone to give you an impartial answer. And this starts right in the title with "you be the juror" -- but it extends all the way to minor points like the use of the term "guilty" which has both legal and colloquial meanings.

I ended up spending a lot of time looking over the two provided sites, without having ever heard of the case before.

The parts of the "true justice" site that I found most helpful were:

http://truejustice.org/ee/index.php?/tjmk/comments/how_the_media_should_approach_the_case_if_justice_is_to_be_done_and_seen_to/

http://www.truejustice.org/ee/index.php?/tjmk/comments/why_defendants_mostly_dont_testify_those_devils_that_lurk_in_the_details/

Whereas the FoA site seemed very well put together.

The primary pieces of evidence that shape my current beliefs (I have admittedly looked through the comments but they've become heterogeneous enough that I don't think they've effected me too much) are:

The FoA site provides a clear outline of possible events, and addresses every outlier I have seen presented. This outline involves the least amount of criminal activity, and so has the highest prior probability for me.

The True Justice site provides a clear outline of possible events, but these events seem to be in contradiction with the FoA events. Specifically, a major point of evidence is the "cleanup phase" which FoA points out was not used by the prosecution--I do not consider the existence of the "cleanup" to be in evidence. The page also involves more conspiracy, giving it a lower prior probability for me.

TJ claims Amanda's confusion about phone calls made is evidence--to me it seems like evidence of her innocence. I would expect an innocent person to be more confused and forgetful than a guilty one. I would expect a guilty person who was covering up to be more aware of content-unrelated details (such as the prosecution's assertion that a call was made at 3am seattle time).

FoA presents specific details about poor police protocol around the crime scene, as well as questioning the use of luminol and citing the prosecution's expert witness. TJ takes "bloody footprints" to be in evidence, I do not believe that they are.

Were I a jurist involved with the trial and were the evidence from these sites all that was presented to me, I would certainly rule that Amanda Knox was innocent, I do not feel that there is sufficient evidence to claim otherwise and cannot comprehend how someone would.

HOWEVER I noticed that 6 Italian judges had considered the case, that she was convicted by a jury, and that Judge Micheli produced a 106 page report on the guilt of RG which indicted RS and AK.

The prosecution has been noted as somewhat crazy, this makes the possibility that the jury wanted to signal disapproval of murder-rape at a level much higher than protect innocent people more probable.

TJ notes that RS and AK stood outside the girls' house the night of November 1. FoA claims that this was unreliable witness testimony.

I therefore believe that there is substantial evidence for the prosecution of which I am unaware, enough to convince 6 judges and a jury, much of which should be in the micheli report which there's no way I will read (106 pages of italian?!)

My beliefs hinge primarily on the believability of the testimony--were RS and AK at the house the night of 11/1, or did AK return the morning of 11/2?

Now, to answer the first four questions:

1. P(AK guilty): 41% P(AK|at scene night of 11/1): 80% P(AK|not at scene): 2%

2. P(RS guilty): 38% P(RS|at scene): 75% P(RS|not at scene): .5%

3. P(RG guilty): 99% P(crazy shit): 1% P(RG guilty| no crazy shit): 99.9999%

4. Since OP has claim to extra information concerning the case, I suspect that OP will be within 20% of my conditional beliefs for 1. and 2. with 70% confidence. Similarly I suspect that my aggregate beliefs (because they are split evenly between "intense anti-murderape-signaling" and "murderape conspiracy") for 1. and 2. will be FURTHER than 20% from OPs beliefs with 80% confidence.

Everyone on both sites and here seems convinced of RG's guilt. I think there's approximately a 1% chance of some crazy shit happening but otherwise this belief is primarily uninvestigated (relies mainly on people not writing 106 page reports about innocent people murdering each other).

For those of you who were not familiar with the case, which side's arguments did you read first?

Did it feel like this order influenced your reasoning or final judgment?

(I read pro-guilt ideas first, and feel now that this ordering contributed to my judgment that Knox and Sollecito are guilty. I wonder how conviction rates would change in the US if we let the defense go first, i.e. what are the relative influence values of the right to speak first vs. last?)

Hello,

I haven't made up my mind yet - and if anyone's interested, this cbs take on it looks well done:

http://www.cbsnews.com/video/watch/?id=5915082n

Context: I didn't know anything about the case; I think I've overheard something about it in the past, because I had a very slight sensation of déjà-vu reading your post, but I didn't really know anything. The info I used was reading the Wikipedia pages (one you linked and one on one of the trials), then skimming the sites you linked for less than a half hour.

I have reached a “decision” about it, but I didn't intend to post it. Then curiosity got the best of me and I read pretty much all the comments already here. My “estimate” wobbled a bit during the reading of the comments, but by the end it converged on its initial value. I decided to post my opinion, as somebody else mentioned, to avoid self-selection.

I used quotes above because my general state is confusion. Actually, it's confusion both about the case and about the poster's opinions (and, a bit, about your post).

The general impression I got was that all parties (except, probably, the victim) are guilty of something, including the prosecutors. But...

First, I'm not very sure exactly if your questions should be translated as “probability estimate that X killed Kercher” or not. I actually have a slight suspicion that your post might be a trick question around that. (In fact, writing now, I realize that the trial resulted in guilty verdicts on ~five counts for each, but after all the reading I have no idea what they are other than that one of each is some kind of murder.)

Regarding Knox and Sollecito, my “gut” impression is that they're guilty of something, in the sense that I'd be quite surprised if they were just two innocent people who did absolutely nothing bad (other than that joint) and got dragged in a nightmare by chance. I also have a “gut” feeling that their “guilt” is correlated.

Regarding Guede, I've got a slightly stronger gut feeling of guilt (than I do for the first two).

I also feel (as in “gut”, again) that the prosecution and trial was “wrong”. (EDIT for clarification: but I can't see any basis of estimating how wrong between “as good as reasonably possible” and “gross miscarriage of justice”.)

However, what confuses me most is the certainty of most estimates I've seen in the comments. I just don't see how one can get much farther than “I don't know, but I lean a bit towards” either way on what the posters report as their information. I mean, after only a couple hours or so of thinking (both during reading and writing this) I'm not even sure what priors might be appropriate. I feel I know so little about the case (including info like trials in general) that my response can't be more than “I don't know”. (If pressed a lot I'd output 0.5±e as a probability, simply because even my knowledge of probabilities is too weak to actually figure out if anything else would express my almost total uncertainty on this subject, and that's my cached answer for binary questions.)

Put differently, given the information I have on the subject, it feels as if the confidence I should assign to any probability estimate should be very close to 0. As I said above, I tend to give probabilities as ~50% in those cases, but that's not exactly a correct description of what I feel. A good description would be that, if forced to bet (without more time to think), I'd bet on all of them being guilty, but if given the option, I wouldn't bet any amount at 1:1 odds.

Oh, and the answer to the fourth question is very similar. Leaving aside the fact that I'm not sure exactly how I'd quantify the “coincidence” of opinions, I'm wouldn't put any significant confidence in any estimate. (The “gut” feeling is that you consider all three guilty, but that's mostly a very vague impression I got from the wording of your text rather than reasoning on my part.)

As an aside, the interesting thing about the subject is that I was surprised how little confidence I assigned to my “estimates” in this case. I usually have some opinion on most questions I encounter, but in this case I find myself really unable to arrive at one.

I've looked at this twice - first after reading the friends of amanda blog, wikipedia, and scanning the justice for meredith blog.

My initial probabilities were: P(AK=guilty) = .55, P(RS=guilty)=.5, P(RG=guilty)=.999, P(views coincide)=.5. Having read a few comments I initially revised the first two probabilities down - I realised I was guilty of having given a lot of weight to the rape story, and not given weight to the improbability of the "weird sex" story.

Having read more I find it hard to be sure of anything - it seems to be next to impossible to get any unbiased information on this (wikipedia contradicts friends of amanda, e.g. on the washing machine and the cleaning operation which are crucial). I would also be astonished if the Italian legal system could encourage such a high-profile miscarriage to take place. Italy is one of the most developed countries in the world. While they do have a mad president, some might say the same about some American presidents. And I have seen clear one-sided bias against the Italian legal system (e.g. the sashes worn by the jury - standard dress for jurists in Italy)

EDIT: Looked at this again. I've got to revise them to .99, .99, .999, .9 Some excerpts from the evidence on this blog - the evidence that FoA discounts looks very real to me. The only thing I find really weird is how the three could have got together. http://boards.insessiontrials.com/showpost.php?p=13695224&postcount=718

By guilty, do we mean "committed or significantly contributed to the murder"?

Or do we mean "committed or significantly contributed to the murder AND there is enough evidence showing that to satisfy the beyond-a-reasonable-doubt (or Italian equivalent) standard of proof for murder"?

The comments don't seem to make that distinction, but I think it could make a big difference.

ak guilty: 0.1

rs guilty: 0.1

rg guilty: 0.9

assessment of my opinion vs poster's opinion: can't guess at your actual probabilities, but probability similar general take identifying guede as vastly more likely to be guilty than the other two.

sources: small number (i estimate <5) of media stories covering the case that i've seen over recent months plus the wikipedia article as it read at a little after 4 pm today.

I spent less than an hour browsing the two links provided and randomly surfing elsewhere afterwards. I was unfamiliar with the case before.

My estimated odds of Raffaele Sollecito being guilty of murder are very roughly 1:1, of Amanda Knox being guilty of murder a little less, of Ruedy Guede being guilty closer to 4:1.

Unfortunately I couldn't entirely avoid having a peek at comments before coming to an estimate - there were some numbers in the right-hand "recent comments" box of the site.

The main driver in my estimates is that all three were convicted. This implies that dozens of people, including a carefully selected jury, spent days poring over all available evidence and came to that conclusion "beyond reasonable doubt", and my own effort in assessing the evidence is necessarily shoddy compared to that.

I started out with about 4:1 to 9:1 confidence in their guilt, given the information provided in the post, which mentioned their conviction.

Then I started reading the Friends of Amanda site, reasoning that evidence mentioned as uncontroversial in a site arguing for the convicted would tend to be solid.

I browsed TJMK for a while as well, my take-away being that the principal question seems to have been whether one person (RG) or several were involved in the killing. I heavily discounted what I'd read there after I came across an article arguing against Amanda Knox on the basis of her liking singer Feist because Feist has published sexy pics.

On balance the evidence against Rudy Guede seemed rather damning, that against the other two much thinner. (Nobody seems to take seriously the idea that there could be something to RG's version of the facts.)

My peek at the comments here might have moved me slightly away from assuming the guilt of the two, perhaps as much as from .6 to .5 probability of guilt.

I suspect, if you think of this as a "rationality litmus test" (I don't, since the odds seem slim that we'll ever get to the bottom of the case, fact-wise), that you have formed an opinion that the two are not guilty.

1. p = 0.5
2. p = 0.5
3. p = 0.95
4. I have pretty high confidence (~95%) that you got the right answer, which doesn't tell me which side you're on for the first two, but means you'll likely agree on the third.

As a disclaimer, I did peek at other peoples comments before writing these down, but I had mentally committed to these numbers before doing so. I had heard of the case a while ago though I never looked into it. I had the impression that Knoxx and Sollecito were guilty (based solely on the fact that they tend to get the right bad guys) and didn't remember hearing about a third person.

I just briefly skimmed the wiki page and the "innocent" site.

The evidence for the guilt of the first two didn't seem very strong, but I'm not familiar enough with forensics to know how much would be expected. There were some things against them (they were found guilty) but I'm gonna have to claim ignorance.

The evidence against Guede was pretty strong. I'm just not comfortable putting numbers higher than 95% because there's a number of unrelated ways that errors can build up.

I'm putting myself in the "low familiarity" category.

1. estimate Amanda Knox is guilty: 40%
2. estimate Raffaele Sollecito is guilty: 40%
3. estimate Rudy Guede is guilty: 90%
4. not confident at all that my estimates correspond to komponisto's

I got most of my information from the "defendants are innocent" link and the Wikipedia article - I found the "defendants guilty" link hard to read or assess. I did not spend much time forming my opinion, just a quick browse.

1. 5%
2. 5%
3. 95%
4. probably generally the same - you might be more or less extreme.
5. The sources are the two sites you linked to, plus the wikipedia article plus my impression that 1 man killing a girl in a sexual assault is a priori much more likely than three relatively recent acquaintances doing same.

NB - 5% and 95% are basically just proxies for 'pretty sure it's not true' and 'pretty sure it's true'. I wouldn't claim that they're anything like well-calibrated. I don't think I form opinions on stories like this often enough to be well-calibrated.

Oh, and I second the opinion that this is exactly the sort of thing that LW needs more of - people actually attempting to see how good they are at being right about the world (although maybe issues in which it's easier to be sure of the "right answer" would be better tests).

I had heard a little about this case before you brought it up, but I didn't want to read about it since I figured I'd get angry about either: 1. Yet another travesty of justice. or: 2. Yet another obviously guilty person being cast in a good light. It was the former. Unrecorded interrogations without a lawyer. No forensic evidence putting Knox in the room. No motive, no sequestered jury, tons of disputes about forensics. What a mess.

Your probability estimate that Amanda Knox is guilty.

0.2

Your probability estimate that Raffaele Sollecito is guilty.

0.25

Your probability estimate that Rudy Guede is guilty.

0.9

How much you think your opinion will turn out to coincide with mine.

I think we'll be rather close. Basically, low probabilities for Knox and Sollecito, and a very high probability for Guede.

I'm moderately familiar with the case (have read a few media articles on the case over the last few months).

1. 10% (weak evidence, lack of motive, low prior probability of female on female sexually motivated violence)
2. 30% (evidence not much better, higher prior probability of male on female sexually motivated violence)
3. 50% (seems to fit profile of this type of offence, evidence of association with victim and opportunity and circumstantial evidence)
4. I expect your relative rankings to be the same, less confidence in absolute probabilities.
5. Fairly mainstream media sources, probably linked from blogs I read which will likely supply a selection bias, don't remember exactly what the sources were.

I have never heard of this case before this post. After approximately 30 minutes of reading the two sites you linked to as well as the Wikipedia article, my current estimates are:

• Knox guilty: 0.35
• Sollecito guilty: 0.35
• Guede guilty: 0.80

I think your opinion will roughly coincide with mine about Guede, but could differ dramatically about the other two.

[comment deleted]

1. How much you think your opinion will turn out to coincide with mine - hard to define. If your respective answers are 10, 40, 90, how much did we agree? I'll guess that the sum of the three differences between my answers and yours is around sixty percentage points [out of 300 possible].

I'm going to have to distinguish here between guilt in the actual sense, and guilt in a legal sense. Do I think Amanda Knox did it? Somewhat likely. Do I think the prosecution proved that beyond a reasonable doubt? No.

I think my estimates of guilt for all three parties will be higher than most commenters, but here they are:

Probability that Knox participated in the murder: 15% Probability that Knox participated in or covered up the murder: 20% Probability that I would find Knox guilty of murder: 5%

Probability that Solecito participated in the murder 10% Probability that Solecito participated in or covered up the murder: 20% Probability that I would find Solecito guilty of murder: 5%

Probability that Rudy Guedo participated in the murder 80% Probability that Rudy Guedo participated in or covered up the murder 95% Probability that I would find Guedo guilty of murder: 85%

The biggest problem to me with the prosecution's case is the alleged physical abuse of Knox by her interrogators. Her story did change somewhat, but not in a manner consistent with a guilty party. If Knox was guilty and wanted to frame someone else, it is unlikely that she would have fingered Lumumba days later and made vague statements that incorporated some kind of clairvoyant dream about Lumumba raping Kerscher rather than just making immediate and damning accusations. If the police physically harmed her in any way, that alone should have been enough to immediately drop the case. I'd find Charlie Manson innocent if I found that the police had roughed him up in interrogation to elicit a confession; such actions by the police undermine the very fabric of a free legal system and cannot be tolerated in any way whatsoever.

Secondly, the prosecution failed to establish a clear motive. First they claimed that Meredith refused to participate in some unspecified 'sex games'. They never showed that Knox or Solecito were inclined to that sort of sexual behavior, and even if they were, it is a large leap from sexual frustration to murder. There was the stolen credit cards and missing money, but it was never shown that Knox or Solecito were in possession of the money. It should have been fairly easy to find a record of their withdrawals from Kerscher's account, but it appears the police never even attempted to find such evidence. So the prosecution claimed that since Knox and Solecito smoked cannabis, they must have been addicts who stole the money (that no one ever proved the couple even had) to fuel their raging drug habits and possibly buy 'hard drugs' like cocaine. Que clips from 'Reefer Madness' now.

There is DNA evidence against Knox, but being roommates with the victim, it would be a challenge to find something of Kerscher's that didn't have some of Knox's DNA on it. This seems to be a case of the 'CSI effect' actually working in favor of the prosecution. All the jury hears is 'DNA', but don't stop to consider any number of explanations as to why Knox's DNA would be on one of her own kitchen knives and on her roommate's clothes that don't involve murder.

There is also some dodgy eyewitness testimony, but even if the witnesses were so-called 'credible witnesses' eyewitnesses are notoriously unreliable.

Guede, on the other hand, used the classic 'a large unidentified black man did it' defense at first but then changed his story when he found out Knox and Solecito were involved. He did flee the country, but so would I if accused of murder in a foreign country. Forensic evidence also confirmed that Guede had sex with Kirscher that night, not rock solid evidence I know, but notable. More evidence against Guede comes from the story he gave of how he was sitting on the toilet listening to his iPod when the attack occurred, which would have meant that he knew about the attack when it happened, failed to call the police, and fled the scene to go dance at a night club. Additionally he originally claimed that he tried to comfort Kerscher, meaning she was still alive, before fleeing and leaving her to die, which is ethically equivalent to murder.

To draw this lengthy post to a conclusion, I'm going to give my first impressions of the site wanting to keep Knox behind bars. As Nietzsche said "Distrust all in whom the impulse to punish is powerful." All of these 'victim rights' groups who spend their time trying to keep other people in prison are a walking contradiction. A murder victim, by definition, has no rights; they're dead. It does a victim no good to keep the murderer behind bars; it only serves to satiate the need for vengeance in the bereaved. True, there are people who will likely murder again if released, but often, these groups continue to hound those who have reformed and express remorse (Leslie Van Houten), or those whose guilt was never clearly established in the first place (Leonard Peltier). Knox seems to be just another one of these unfortunate victims getting slandered by those who confuse justice with revenge. Am I out on a limb here, or does someone want to present a rational case for rights post-mortem?

How does one get to vote? I say, not guilty except Guede. What an embarrassment and nobody wants to admit their crooked government employees are nuts and criminals. Someone needs to look closely at Mignini and his motives, He sounds like a religious nut whose small mind saw one thing and then spoon fed the tabloids. And found guilty of "crimes in regard to evidence". This is a complex case. These two do not deserve to be in jail. Guede does and then the Perugian Magistrate, prosecutor and the tabloids should be held accountable for the crimes against these two. The Anti-american bias and bigotry, the ridiculous deal made with Guede, the ridiculous "slander" suits, Amanda should bring her own, if this doesn't scream slander........hope the people see the truth, even if an attorney who really has nothing but money to gain, he represents most of the "slander" suit plaintiffs and will then be awarded money against those monetary awards. Does he have a "Knox" motive? You know, the motive where you are judged, tried in the papers then smacked around, sleep deprived, food deprived, ATTORNEY deprived.....you can't tell them any other way, become the easiest target by finding a problem, calling the police. A truer criminal you will never find? She didn't exactly fight against the review of the forensics and DNA, a guilty person would probably be pretty upset. Just a little DNA in the wrong place...Oh, Rudy Guede and his huge amount of DNA that was found including feet and handprints, then their is that hair and sexual stuff...... This case is the one in a million where jurors were probably threatened to vote guilty, See how that baseless rumor starts.........Hmmmm I do wonder just what is true, with the now tainted background of the prosecutor and his lady friend. Just a thought

I have had a ringside seat to this debacle for three years and have never doubted the innocence of Amanda and Raff for even a day.

What is troubling is the number of folks out there who WANT to believe in their guilt without ever reading the information available to everyone reading this.

Amanda and Raff 0.00000% guilt Rudy 100.0000000% guilt.

The actual facts bear witness to my opinion. The Smear Campaign that occurred in the first three weeks after the murder continues to perpetuate the false opinion that these two innocent college students are depraved.

The Smear is unabated to this day. That is why so many good, intelligent folks have that tiny bit of doubt. It's a damn shame. But friends and family will continue to work very hard to correct the public perception, so that when these kids come home they will not have to deal with wackos. His DNA is all over that room, Miss Meredith had the ill fortune to walk into a burglary in progress and lost her sweet life for that reason.

I have a ring side seat to this debacle and have never doubted Amanda and Raff's innocence. It is heartbreaking to see how many people WANT to believe they are guilty without ever taking the time to study the facts of the case. Most of which is at the fingertips of everyone reading this.

I find it a very simple case with tons of evidence and tons of lack of evidence that point to freedom. And to something SERIOUSLY wrong somewhere. I love America, I love Italy, I love truth and hate injustice. Fact over opinion. Show many facts...

I find it a very simple case with tons of evidence and tons of lack of evidence that, to me, make any other scenario bizarre.

I'd love to know what Amanda and Raffaelle got up to that night but the lack of DNA in the room and on the body suggests that whatever they did, they weren't in the room or directly responsible for the death, and nor did they go back in the room to move the body around - that would require head to toe covering. But...

Did Amanda and Raffaelle sit in the flat egging Guede on, not realising the screams were real? Or, worse, did they laugh knowlingly when they heard screams?

What would they be guilty of? Would either scenario count as murder?

Did they feel so sure that they would be acquitted that they didn't own up to being in the flat?

If they owned up now, could the courts increase the sentence to 30 years for having perjured themselves, even if it wasn't classed as murder?

Or, are they just two idiotic and/or idealistic students who don't make sense, can't make sense?

Not very familiar -- had heard about it, but no real details.

I'll echo all those that have raised concerns about prosecutorial and police misconduct, releasing details that later turned out not to be true, or were entirely irrelevant. The group sex games focus also reminds me strongly of many other moral panic cases where people flip out for no good reason.

I don't find the "cleaning" hypothesis very well supported -- it's hard to selectively clean, which would be necessary to eliminate all of their own evidence, but still leave so much Guede evidence.

overall: P(Knox) ~ 0.02 P(Sollecito) ~ 0.02 P(Guede) ~ 0.98

I was aware of the case before, but hadn't looked into it in any detail. My reaction to the sites is that the site arguing innocence seems to be presenting facts and showing contradictions in the other side's arguments. I couldn't find any consistent argument on the other side. There were many scenarios, with inconsistent adherence to the facts, lots of innuendo and plausibility arguments for particular claims, but no coherent story.

1. Your probability estimate that Amanda Knox is guilty. less than 30%
2. Your probability estimate that Raffaele Sollecito is guilty. less than 30%
3. Your probability estimate that Rudy Guede is guilty. more than 40%
4. How much you think your opinion will turn out to coincide with mine. It seems likely. more than 75% overlap, if that means anything.

I basically agree with Lordweiner. 90/90/99.

It seems pretty clear that AK and RS were and are hiding something damaging to them. Their stories are just too changing and contradictory.

That damaging fact is almost certainly that they were involved in the murder. Because if it were something else, they would have to be insane not to come clean about it.

ETA: I came up with my estimate before reading anyone's posts.

I don't remember hearing about this case before reading this post. This is not strong evidence that I hadn't; it's the kind of news item I'd be likely to classify as "contains no valuable or interesting information" (no disrespect to the victim, her friends or her relatives is intended; but the global death rate is such that you just can't keep up with all the individual instances, and therefore you necessarily have to be extremely selective about which individual deaths receive any specific attention from you) and discard immediately from memory. In any case I don't have any significant prior case-specific knowledge.

I've consulted the Wikipedia article, one of the news articles used as a primary source by said article, read most of entries from the TJ Prosecution's Case category, as well as the FOA pages. Altogether I spent a few hours on this research.

I accidentally looked at one response (IIRC it was this one) before I read the post itself, and learned that that had been a bad move. I'll do my best to filter that knowledge out of my answer. Since there's accusations of Anti-US bias flying around, I should probably also mention that I'm a citizen of (and live in) Germany. I don't think I'm biased against US citizens, but such self-assessment is always tricky.

Given all of that, here's my answers:

1. 0.8
2. 0.8
3. 0.9
4. It's hard to quantify this precisely. I expect about a 80% chance of you agreeing that the probability for 3 is >= 0.75, and around a 60% chance of you assigning probabilities of >= 0.6 to both of 1 and 2.

Reasoning:

• 1 and 2: Suspects' behavior as documented by their phone and computer use doesn't match their preferred stories. AK correctly mentioning MK screaming is some evidence that she was at the scene of the crime. FOA attacks the DNA test performed on the knife, but the experts responsible appear to think that this kind of testing is reliable under the circumstances, and they should be in a good position to judge. The jury in the case had better access to the evidence available (apparently presenting all of it took on the order of 200 hours; this suggests there's quite a lot of the stuff), and much more cputime to process it than I do; in absence of strong evidence that their reasoning was fundamentally flawed, their judgement is strong empirical evidence for the guilt of the defendants.

• 3: Pretty good evidence there; lots of DNA material, and RG's story sounds rather unlikely. And again, there's an existing judgement by someone who had better access to information and more time to think about the issue.

General comments:

This is quite a mess. Both of the advocacy sites are contaminated with lots of data that's so weakly relevant as to be basically a distraction. So are the newspaper articles. Why exactly do we need photos of the people involved? Even hypothetically, what does this kind of information add to the discussion? The character testimonies are only marginally better; theoretically that kind of thing is evidence, in practice it's so weak as to be likely to do more harm than good. This whole case is an affect minefield. I guess this does make this a great real-life rationality stress test, but somehow I doubt that that was what the people who put those documents together had in mind.

AK guilty: 90%; RS guilty; 85%; RG guilty: 99%. Probability that komponisto agrees that they are all probably guilty: 80%.

The more I read, the more it seems to me that the "pro-guilt" side has a case like the scientific case for the "pro-evolution" position, namely conclusive arguments that take a while to understand, while the "pro-innocence" side has a case like that for creationism, namely plausible arguments that do not stand up under scrutiny.

Evidence that komponisto agrees with this is another accidental similarity with this case: creationism is a popular American position, while the scientific community knows that evolution is true. Similarly, the pro-innocence side of this case is a popular American position-- in fact adopted by most of the posters here-- but those who have actually studied the case, namely the judges and jury, thought themselces to be convinced beyond reasonable doubt that the three were guilty.

Does anyone else think that if Knox is innocent she only has herself to blame for changing her story so many times and for implicating an innocent man?

Maybe that's harsh of me to say and if she is innocent she obviously doesn't deserve jail but it's kind of hard to feel sorry for her.

1:25% 2:25% 3:50% 4:60% on 1&2

I knew virtually nothing about this an hour ago.

I didn't know anything about this case until I read this post.

My first impression: Wow, there sure is a lot of information on what a nice person Meredith Kercher was on that one site, and what a nice person Amanda Knox is on that other site. (The latter is at least potentially relevant, if you think a nasty person is more likely to kill someone.)

Anyway: Knox : ~35%; Sollecito : ~35%; Guede : ~95%. And I'd say it's about 60% that all of these probabilities are on the same side of 50% as yours.

(I had a bunch of information here on how I came to my opinion, but I don't think it's really important. Suffice it to say that the evidence I've seen against Ms. Knox and Mr. Sollecito is pretty terrible, but the evidence I haven't seen may be much better.)

Anyway, if those are the best, clearest sources available to me then I am pretty doubtful of my ability to form a useful opinion on this case at all.

Both sites are sources of information presented by people with extremely strong emotional investments in the case. The Guilty site seems to be populated by nothing but emotional arguments (even looking through the Micheli Report link only produced second-hand commentary couched in strong emotional terms, i.e., "our translators cried..."). The innocent site is less emotional. Neither provide objective third-party sources of information, so taking either side's arguments as "facts" seems to be undertaking a bias to begin with.

Even after killing an hour going through the sites, I'd have to abstain.

I attempted the test with zero familiarity with the case at hand. I also have very little knowledge of the Italian justice system.

One major problem in presenting a probability assessement is that the links presented in the post offer pratically no facts about the case. They are about a Washington Senator's reaction, instead. It would be ludicrous to answer the questions asked given only this information.

So, I went googling around for more information. I promptly hit a snag in that I do not what a fast-track trial is in the context of Italy, and searching for information on that is made very difficult since the search returns articles on the Kercher case.

Attempting to filter out all the extra fluff about the characters involved, the facts of the case, most especially the DNA, seems to point to Guede. There is no hard evidence supporting Knox's guilt, and Sollecito's DNA on the victim's bra is not suprising given their relationship.

Unless the links I read (mostly obtained via Wikipedia) managed to omit something important, I'd say the following:

Knox guilty: less than 0.1 Sollecito: 0.1 to 0.15 Guede: 0.9

1. Your probability estimate that Amanda Knox is guilty.

0.05

1. Your probability estimate that Raffaele Sollecito is guilty.

0.05

1. Your probability estimate that Rudy Guede is guilty.

0.9

1. How much you think your opinion will turn out to coincide with mine.

p(same direction) = 0.6

p(someone in the prosecution is guilty of actions I would give live imprisonment for) = 0.99.

It's good that you gave two separate links to look at both sides of the case. However, I really disagree with you suggesting people to look at wikipedia. Wikipedia is known to be horrifically unreliable when it comes to controversial topics. This much can easily be seen just by scrolling through the article's "discussion" subpage, which contains a lot of ouright allegations of impartiality from various wikipedia editors. I've seen a few people posting their assessments based on their reading of wikipedia, and this is a big problem.

For further illustration of the impartiality of wikipedia in controversial topics, perhaps the best example I have seen is the article for second hand smoking, which they label as "passive smoking" (http://en.wikipedia.org/wiki/Passive_smoking). See pertinent criticism at (http://tech.slashdot.org/comments.pl?sid=1346195&cid=29182695). If you read the article (and the commentary subpage), it is pretty outlandish how one-sided it is.

You need to actively discourage people from looking at wikipedia for this sort of thing...

I haven't followed the instructions precisely, due to lack of time, but will answer anyway in the interest of avoiding self-selection bias. (I'm also not reading any of the other responses yet.)

I had heard of the case, but not seen any mainstream media reports. It was probably on one of the blogs I read.

I spent about 5 minutes looking at the "guilty" site, and about 1 minute looking at the "innocent" site. My first reactions to the two sites were:

(1) Wow, the "innocent" people aren't really trying very hard. Is this really the best, most passionate defense out ther? Is komponisto actually playing some sort of rationalist psychological game here, where the real test is to see if we notice how lame the defense is? Hmm, maybe not, because we are advised that it's ok to look elsewhere...

(2) The "guilty" site is disorganized, but apparently full of information. Or is it really? It mostly seems to be emotional reactions, not a description of what they believed actually happened and why. Possibly that information is on one of those fifty-zillion pages, but gee -- if my friend had been murdered, and I wanted to make sure that her killers were brought to justice, I would make damn sure that the facts were front and center, with as many sources as possible, and that the arguments were crystal-clear. Then I would get into the emotionalizing about how terrible this is. But hey, I'm a Vulcan*, maybe this is normal behavior for grieving humans.

(*according to some people, and sometimes I don't know how serious they are)

So, to answer the enumerated questions:

1. High, but with a large margin of error.
2. High, but with somewhat less large (but still significant) margin of error
3. Somewhat higher than #1, but also with an even higher margin of error -- he wouldn't be subject to "anti-American bias" (thus indicating that a guilty verdict is more likely accurate), but he also doesn't have any high-powered advocates fighting for him (a false accusation would be less likely to be challenged) and wouldn't enjoy the protection of being American (which is kind of the opposite of the "anti-American bias" claim, but matches what I have heard about how Americans are handled by foreign legal systems -- i.e. more carefully than locals).
4. Well, you've done a pretty good job of concealing your beliefs by the way you've couched the argument... unless the fact that the "innocent" site is so lame is a giveaway... on the other hand, you might have spent more time on the "guilty" site than I did, and found clearer reasons to either believe or distrust it. 60% likelihood?

There's the obvious conclusion of "white American privilege is the only thing supporting Amanda Knox's case -- but that would be extremely circumstantial, and has been proven wrong before (e.g. the Duke LaCrosse scandal took place just a few miles from where I live). I want to know what the real argument is, and I'm not finding it -- but I recognize that I haven't yet taken the time to do a proper search.

Okay, that's probably more data than you wanted for a largely inconclusive result.

UPDATE after reading some comments: I didn't notice that one of the links to the side on the "innocent" site had more information; my initial assumption was that they were all translations of the front page. Clicking on that link immediately takes me to a summary which seems much more clear-headed than anything on the "guilty" site, and actually gives a few facts involved in the case. A further link (clearly labeled) goes into considerably more detail.

After reading about a third of the detailed account, my estimates of Amanda and Raffaele's innocence goes up considerably (with accompanying reduction in the margin of error), along with my estimate of Guede's guilt.

However, before making a final determination I would want a great deal more information (e.g. recordings of the police interrogation, or transcripts, or whatever is available), considerable quiet time in which to ponder it, and a chance to ask any questions I might think of.

I was unfamiliar with the case. I came up with: 1 - 20% 2 - 20% 3 - 96% 4 - probably in the same direction, but no idea how confident you were.

From reading other comments, it seems like I put a different interpretation on the numbers than most people. Mine were based on times in the past that I've formed an opinion from secondhand sources (blogs etc.) on a controversial issue like this, and then later reversed that opinion after learning many more facts.

(I didn't put any evidential weight on the jury's ruling. Conditioning on the simple fact that their ruling is controversial screens off most of its value.)

I think this is an interesting exercise which can be quite useful even if we can't find the answer in the back of the book afterwards.

It'd also be interesting to see what everyones second guess is, after conditioning on the beliefs in the comments.

I'm now "pretty sure" that Knox and Sollecito are innocent and Guede is guilty, though I'd have to think a bit in order to translate to numbers.

My familiarity with the case is low:

1. p = 0.40

2. p = 0.40

3. p = 0.90

4. I think we will agree with the general idea that Guede is likely to be guilty while Knox and Sollecito are unlikely to be guilty.

From what I could gather, the physical evidence against Knox and Sollecito is pretty weak and the force of the prosecution's argument is supposed to come from the inconsistencies between Knox's and Sollecito's accounts of the night. While there were more inconsistencies than I would have expected (judging just on the general fallibility of human memory), I felt that Knox's alibi of being exposed to extended interrogation was enough to account for the inconsistencies.

One potential problem is that the first site is organized like a blog or forum, and thus it is hard to find a quick summary of the case there.

Orin Kerr thinks (or dreams) that's the future of legal briefs.

I didn't read the material and don't have an opinion. I had heard of the case before from sources pushing for innocence.

This might be a naive question, but why hasn't Guede cleared up any confusion about Amanda's/Raffaele's involvement? This seems important enough that the police/prosecution would somehow make him cooperate if he's refusing to (e.g. strike some deal or something).

1. Amanda Knox guilty: .85
2. Raffele Sollecito guilty: .6
3. Rudy Guede guilty: .2
4. Similar opinion: .6
5. Information: Your links

Sorry, but I looked at both websites, and determined there's no way I'm reading that much material just for a little dubious calibrating. I'd rather calibrate on something where the outcome can be determined.

No opinion on the case, but I notice a lot of people are giving guilt probabilities that sum to well over 100%. Unless they are figuring in the options (two of these three are guilty) and (all three are guilty), this seems a bit off. Also, these options are apparently being given quite high implicit probabilities, sufficiently so that they should perhaps have been listed explicitly.

none of my business. am I alone in thinking that justice is between victims and perpetrators and the rest of us don't need to have an opinion?

is the idea behind this post that us rationalists should be judges, as we are more qualified as impartial arbiters than others? I'd hesitate to claim competency in such an unfamiliar and broad domain space as being a judge. I guess most don't find the domain space "unfamiliar" since they envision themselves as the ultimate arbiter on a daily basis.