Amanda Knox Guilty Again

Would the natural experiment of DNA evidence furnish the false positive rate you are interested in?

Has any government ever investigated the rate of false positives in a jury system by faking trials? ... Would this be a worthwhile thing to do?

It's probably worthwhile, but the purpose of a jury was not to improve accuracy. After all, you could just have one or more judges, who would have more experience and thus be less prone to error, determine guilt instead of a jury. The purpose of a jury was to make corruption more difficult (harder to secretly bribe a dozen randomly selected citizens), and to provide a way for the people to negate laws they don't like (can't punish juror for declaring someone innocent).

So even if there were a more accurate way to produce verdicts, there are other factors to consider.

Has any government ever investigated the rate of false positives in a jury system by faking trials?

The incentives of a government are more likely to be in suppressing such information than uncovering it. (Crudely speaking) the government wants people to perceive that just is done. Actually doing justice is just one way of achieving that perception.

There should be experiments on different ways of deciding guilt to see which are most accurate. My understanding is that most of the current system was created centuries ago, and wasn't the result of experimentation.

We should determine the optimal number of people on a jury, and whether juries get better results with various selections of jurors (paid professional jurors or drafted jurors, high-IQ jurors or low-IQ jurors, old or young, diverse along various dimensions or not, etc.).

The point of jury trial is NOT to maximize the chances of a correct verdict, just as the point of democracy is NOT to generate optimal policies.

I agree with your final prediction but not with your reasoning. The United States will likely not allow Knox to be extradited, not due to a vague sense of reluctance or unquantifiable dislike of Italy, but because the US has explicit laws that not allow extraditions relating to double-jeopardy. Any country wanting to extradite someone due to a crime for which they have previously been found innocent will be ignored. So in fact, the US would actually have to find a procedural excuse to allow the extradition request.

It's confusing to call making of unverifiable predictions a "bad habit" (not specific, noncentral); it just doesn't have the additional benefit of teaching you calibration. Learning from verified predictions is one of multiple things that can be done to improve the accuracy of predictions, including unverifiable ones. If you are making very long-term verifiable predictions, there is little opportunity to learn from their verification, so in this case the distinction breaks down.

Additionally, according to Wikipedia,

The Court of Cassation cannot overrule the trial court's interpretation of the evidence but can correct a lower court's interpretation or application of the law.

so there is not nearly as much latitude in what the court can do

...except that they already did completely overrule the trial court's interpretation of the evidence when they canceled the acquittal last March. So, they could certainly do it again, in the opposite direction, if they were so inclined. (I'm not predicting they will be so inclined.)

In Italy, the "interpretation or application of the law" includes the reasoning about the evidence used by the lower court; this is the loophole they use to disagree with lower courts about the facts of the case when they feel like it.

In a country which repeatedly elected a known criminal who escaped conviction through various shady means to the top post

blushes with embarrassment

The important question here is, can the supreme court say that the evidence does not meet the standard of reasonable doubt? Is that a matter of interpretation of the evidence, or a matter of the application of the law?

The Guardian video with Simon Hattenstone, featuring Knox and her best friend Madison Paxton, is highly recommended.

Contingent on losing her appeal, Amanda Knox will be extradited to Italy to serve her sentence.

I've noticed that this kind of formulation of a prediction is defective for the purpose of calibration on things like predictionbook. If, instead the prediction was "Amanda Knox will be lose the appeals process AND Amanda Knox will be extradited", to complement your other question then the predictions continue to mean what predictionbook intends them to mean and if people answer both predictions then they have also provident the conditional prediction information.

Contingent on losing her appeal,

This is ambiguous, of course; technically, the "appeal" level is what just happened. The next stage is a second "appeal", at the Supreme Court. (Italian terminology actually uses two different words for the two stages, but they both translate as "appeal" in English.)

Amanda Knox will be found guilty by the Italian Supreme Court.

Again, to be technically correct, what would happen is that the finding of guilt by the appeals court (the thing that just happened) would be confirmed by the Supreme Court.

...because if you're talking about practicalities instead of legal formalisms, what actually happened was that Amanda Knox and Raffaele Sollecito were found guilty by the Italian Supreme Court last March.

Police took him from a hotel to a police station about 1 a.m. to stamp his passport in a way that would prevent him from leaving the country.

This confuses me, because Italy is in the Schengen area, where you don't need a passport to travel between participating countries. Presumably they can stop him from easily leaving Schengen though, and presumably extradition treaties are in force.

Sollecito's lawyer told ABC News that he was not trying to flee the country.

This prompts me to ask what the heck he was doing in the country in the first place. In the years since Knox and Sollecito were released has Sollecito been prevented from leaving the country? If not then why in the heck would he stay in that place? Flee! Escape! Buy a citizenship in another country if you must. If that doesn't work then buy a fake identity in another country. You don't stay there and let them target you again.

I'm annoyed that various news sources are reporting that he was picked up "near the Austrian border" as if that implies he was fleeing the country. I bet 60-70% of the population of Italy is as close to the border as Venzone is (roughly 70km).

EDIT: Now another news source is reporting that he may have actually crossed the border into Villach (the shorter route I mention later), which explains why people believe he was fleeing the country.

Particularly to parties informed on the subject: Can someone explain the court's reasoning?

As is usual in the Italian system, the court itself will publish its "motivations" within 90 days.

I can't quite follow why Knox and Sollecito were first convicted, then acquitted and yet are convicted once again.

If by "why" you mean "how it is procedurally possible", that can of course be answered now. Italian "trials" have three stages: first-level court, second-level court, and Supreme Court . The original first-level verdict (December 2009) was a conviction (this was the occasion of my original posts here); that was then changed to an acquittal at the second level (October 2011); that acquittal was then canceled by the Supreme Court (March 2013), who ordered a new second-level trial, which has now ended in another conviction. The case will thus go back to the Supreme Court again over the next year or so.

(Yes, this process could theoretically go on forever -- but in real life, what's going to happen is that now that the Supreme Court has gotten the verdict it wanted, it will rubber-stamp it without fuss.)

Vagaries of the Italian justice system combined with a heady mix of mob justice and nationalism.

Can someone explain the court's reasoning? I can't quite follow why Knox and Sollecito were first convicted, then acquitted and yet are convicted once again.

Are you asking about the actual evidence against them? Or more about the procedural path the case took?