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komponisto comments on The Amanda Knox Test: How an Hour on the Internet Beats a Year in the Courtroom - Less Wrong

42 Post author: komponisto 13 December 2009 04:16AM

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Comment author: komponisto 15 January 2010 09:05:37PM *  4 points [-]

(3) Object-level arguments from a few people who (still) think there is a significant chance Knox and Sollecito are guilty.

There don't appear to be many LW regulars who assign high probabilities to Knox and Sollecito's guilt. There are a few who remain apprehensive about doubting the rationality of the jury or of people like Judge Micheli (the judge in the Guede case) to the extent of lowering the probability of guilt to single digits of percentage; but mainly, they agree that acquittal is called for. My remarks here will thus be directed mostly at people chancing upon this post from outside.

It is incorrect to assume, as some people have, that because I didn't mention various facts about the case in this post, that I am therefore unacquainted with them. On the contrary. However, I do assert that the essence of the case -- the decisive information -- is just what I presented here. Among my main points was that people have been distracted by various other details to the point of getting the wrong answer. The central case in point would be the eight members of the Perugian jury, who despite hearing all kinds of information over the course of nearly a year, were unable to sort out the clutter from the essential facts, which are these:

  • The prior probability of Knox and Sollecito having committed murder is extremely low; of having committed this particular kind of murder, even lower.

  • Since Guede is unquestionably responsible, the mere fact of Kercher's death does not need to be explained.

  • There is no evidence that Knox was in Kercher's room on the night of the crime, and almost no evidence that Sollecito was.

  • There is almost no evidence of any association between Knox and Guede, still less of any between Sollecito and Guede.

  • There is no evidence of antipathy toward Kercher on the part of Knox or Sollecito, or of any other plausible motive for the crime.

  • Every piece of apparently strong prosecutorial evidence has either been totally discredited or is subject to serious doubt (examples: footprints, "mixed" blood, knife, bra clasp, cleanup,...).

  • The remaining prosecution case consists of odd physical facts that are nowhere near as strange as Knox or Sollecito being guilty (broken window circumstances, apparent rearrangement of scene), dubious psychological inferences (inconsistencies => cover-up, cartwheels => not sad, not sad => guilty), and outright non-sequiturs (Knox named Lumumba & Lumumba innocent => Knox hiding something).

  • Knox and Sollecito (along with Lumumba) were suspects before Guede was; the basic theory of the crime was not revised when Guede was discovered.

The above facts are indisputable; there can be little question about which way the winds of evidence blow in this case. Yes, there are lots more detailed facts you can learn about the case (and I know a bunch of them), but as regards the question of who is guilty and who is not, the above is what you need to know, and the rest is noise.

Comment author: rolf_nelson 01 February 2010 08:41:25PM *  -1 points [-]


Given that AK's roommate is dead, a break-in was staged, and the coroner's report showed multiple attackers, the prior on AK being a murderer of Meredith is rather high. On the other hand, if we throw away all known evidence, the prior of AK (or Guede, for that matter) being a murderer of Meredith is less than one in a trillion. I claim the former approach, where you use evidence rather than ignore it when it's inconvenient, is preferable. [Edit: OK, that was too snarky. Let me instead say that you should start with a tighter prior rather than a looser prior where possible; it makes the math more tractable.]

That said, I think our main disagreement is on whether the prosecutorial evidence holds up.

  1. Why do you believe DNA evidence flies around so easily? Quick tests: Do you find your beliefs about DNA match up with how DNA is used to draw conclusions in any other court cases that you're familiar with? Why was RS and the other roommate's DNA not found in more areas? Google any video of a DNA testing lab. Are they wearing hazmat suits and, if not, why aren't the testers contaminating their own samples left and right?

  2. I disagree the five pieces of evidence you listed (footprints, DNA-mixed blood, knife, bra clasp, cleanup) are discredited. I am interested in hearing why you personally believe each of them is not strong evidence. [Edit: if you limit yourself to one item, my order of preference is DNA-mixed blood, then knife, then bra clasp.)]

  3. Outside of those five pieces of evidence, I also think you're being too dismissive of the other pieces of evidence. For example, why is Knox naming Lumumba a non-sequitur?

  4. If the basic theory was that multiple people, including at least one roommate, killed MK, then there was no reason to abandon that basic theory upon discovering Guede.

Am I correct in that one of our disagreements is this:

Observation: AK claimed she saw Lumumba kill Meredith. Lumumba was therefore detained by the police based on her affidavit, but Lumumba turned out to be innocent.

Your conclusion: The presence of this false accusation decreases the probability of AK's guilt (?!) (Because it somehow leads credence to a railroading theory? You may be buying into a false FoA meme that the prosecution merely replaced Lumumba with Guede to save face.)

My conclusion: The presence of this false accusation increases the probability of AK's guilt.

Comment author: Jack 01 February 2010 11:48:53PM 9 points [-]

My ADHD brain lost interest in this after the huge discussion here covered pretty much everything having to do with the trial. And komponisto knows this stuff way better than I do so I'll let him respond. But nearly all of the regulars here looked at the exact same evidence you are bringing up now and nearly all of us eventually concluded that it was more likely than not that AK was innocent. Moreover, I specifically recall discussions of every single point you bring up and I believe every single one was resolved. So you might want to look back at the comments to the original post (the test of your rationality one) before you make komponisto go through all this again.

Since I was heavily involved in the discussion of the Lumumba 'accusation' I'll just add this: If AK and RS cleaned up their own involvement with the crime, but intentionally left the evidence implicating Guede wtf would AK not just accuse him to begin with? It seems likely bordering on obvious that AK was interviewed under duress, that the police had seen her text to Lumumba as implicating evidence and fed her his guilt. As a result, AK either made up or dreamed this bizarre pseudo-memory in which Lumumba was present. Then when Lumumba was cleared and an actual suspect was found they kept AK in their hypothesis so as to not totally embarrass themselves. Indeed, this explanation is one of the few parts of the story where I feel like I can account for every single fact and where no other particularly different explanation makes sense. Even if Knox did kill Kercher I would still assign this kind of story a high probability.