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Bad science and bad statistics in the courtroom convict innocent people

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Re: Bad science and bad statistics in the courtroom convict innocent people

#51

Post by klyrs »

graphe wrote: post #42
klyrs wrote: post #14

Earlier quoted context omitted.

This is magical thinking. We know the guy was bad so we locked him up for a crime. We don't know if we pinned the right crime on him or not, but he's locked away safely now so he must be bad. If this is your genuine belief, it begs the question: why are Americans, on average, such terrible people when compared to other first world citizens?

You don’t just decide to lock someone up for a crime. Police gather evidence, give it to a prosecutor, the prosecutor makes a case (or not) and they will either go to trial or plea, then it’s in the hands of a jury or judge. Claiming guilt to plea down to avoid a case is a problem, but that isn’t the case you’re making. There’s nothing magical about criminal prosecution.

> If you’re looking for the criminal that killed a bunch of people but not that specific case it’s not that uncommon.

Here you're saying that mass-murderers are common, but despite their extensive trails of corpses, we can't pin the actual crime on an actual criminal. No, there's nothing magical about criminal prosecution here, it's no more than bullshit as you've described it.

Back to my question, why do you think mass-murderers are so incredibly overrepresented in the American population?

Re: Bad science and bad statistics in the courtroom convict innocent people

#52

Post by pc86 »

lkbm wrote: post #18

The first time I remember running across this was /Innumeracy/ (1988) by John Allen Paulos. It's been discussed for decades, and as best I can tell hasn't really been addressed at all. I don't know the solution. Ideally, everyone would be good at math, but I don't see that happening in the near future. My best answer is for us to provide every court have an on-call statistician, reviewing every case. I would hope big…

> My best answer is for us to provide every court have an on-call statistician, reviewing every case.

Is this not the exact reason for expert witnesses?

Re: Bad science and bad statistics in the courtroom convict innocent people

#53

Post by chaps »

Very, very much yes. Criminal courts really, really aren't a good place to address technical matters. For example, ankle electronic monitoring (obviously) doesn't work well in faraday-cage like apartment complexes. And yet time and time again, GPS skew is used to argue that someone left their home -- sometimes even months after the fact. I've read emails from a local sheriff's office that said that they consider a sufficiently weak signal to be a result of "foiling", period. Through FOIA though, I've been able to get over 100 million instances where a GPS device didn't have a strong enough signal. There are even criminal trials where an EM company will send a sales person to testify and to claim that they're not aware of any technical faults with the system.

https://thetriibe.com/2022/11/many-on-house-arrest-in-cook-c... (disclaimer: I'm the author)

Re: Bad science and bad statistics in the courtroom convict innocent people

#54

Post by rightbyte »

It wouldn't surprise me if computer forsensics is about as bad science as bullet forsensics.

Ever since I had a porn virus hosting kinda lame porn videos over BitTorrent like 20 years ago, I thought about exactly how computer forsensics prove intent in child sexual abuse material cases.

Re: Bad science and bad statistics in the courtroom convict innocent people

#55

Post by andrewla »

graphe wrote: post #7
causal wrote: post #5

It would be hard to really know, but I'm curious what percentage of the total US prison population is innocent. Per capita prison rate is still around 5 in 1000 according to Wikipedia, which is very high for the developed world.

Innocent meaning they didn’t do the specific crime, or innocent as in someone with a clean record that was railroaded? If you’re looking for the criminal that killed a bunch of people but not that specific case it’s not that uncommon. If you’re looking for a squeaky clean guy that was there at the wrong place at the wrong time it’s very rare. Most criminals are repeat offenders.

This is frequently cited by law enforcement and criminal justice officials, but this is an impossible bar to set, because they have not been convicted of those other unspecified crimes. The excuse "he maybe didn't rob this store, but he did rob those other stores, so let's nudge the case a bit", even if done in good faith by law enforcement, is still fishy, because ... why not convict them instead for the other crimes being purported, since we're more confident about them?

In many cases I think this is likely to be a post facto rationalization for the fact that the case against the suspect is weaker than initially thought but represents a great deal of manpower that feels wasted if the suspect is not convicted.

Re: Bad science and bad statistics in the courtroom convict innocent people

#56

Post by thfuran »

Lord-Jobo wrote: post #20
adamsb6 wrote: post #17

Even photo and video evidence suffers from courtrooms that don’t understand how nearly all cameras will record and encode images. JPEG encoding (and thus MPEG encoding) takes 8x8 blocks of pixels and represents them as a discrete cosine transform. In a very real way these pixels don’t actually exist. If your video evidence relies on such a small portion of MPEG encoded video, you can easily mislead a jury to convicti…

This is one of the better litmus tests to see if the expert witness is knowledgeable in the field, and more importantly, up-to-date on the tech. some really smart but definitely older expert witnesses will fumble this very hard. Its not like those kinds of processes, the "enhancing" filters, are inherently bad or inadmissible, you just have to be clear with the judge and jury what the hell is actually happening.

>This is one of the better litmus tests to see if the expert witness is knowledgeable in the field, and more importantly, up-to-date on the tech

It's an absolute travesty that it should fall to expert witnesses at all. Judges, police, and criminal trial lawyers should know how common forms of evidence work in general.

Re: Bad science and bad statistics in the courtroom convict innocent people

#57

Post by cafard »

10000truths wrote: post #31
WalterBright wrote: post #29

I read about a case once where a man was convicted of rape. The evidence was that the rape was done face-to-face with the victim, and the victim positively ID'd him. How could she not, when she was face-to-face with him? It was a slam dunk. After some years in prison, the convicted person managed to get a DNA test, which proved he was not the rapist. How could this be? It turns out the DNA matched a convicted sex off…

Do you have a link to the case details? At the very least, there has to have been some additional evidence to convict, even if circumstantial. I find it hard to believe that someone can be ruled guilty of a crime as serious as rape based solely on the plaintiff's testimony.

Was this the case involving Alice Sebold? The man was cleared, but I don't remember whether DNA evidence was involved.

Re: Bad science and bad statistics in the courtroom convict innocent people

#58

Post by WaitWaitWha »

sneak wrote: post #4

The police and prosecution are the ones using these tools to attack innocent people. The article opens with a case of the corrupt prosecution intentionally and illegally withholding evidence. This isn’t about bad science, this is about bad prosecutors who are more interested in convictions than justice. Selective enforcement and opportunities to engage in misconduct like this are endemic in the US criminal justice sy…

> The police and prosecution are the ones using these tools to attack innocent people.

... and the defense fails to hire their own expert witness, or use same exact method to keep people out of prison.

(Remember "If it doesn't fit, you must acquit"? Cochran did not come up with it by himself, but an expert provided it to him, the glove not fitting.)

Assuming you are talking about US, adversarial courts.

Re: Bad science and bad statistics in the courtroom convict innocent people

#59

Post by michaelt »

graphe wrote: post #36
WalterBright wrote: post #29

I read about a case once where a man was convicted of rape. The evidence was that the rape was done face-to-face with the victim, and the victim positively ID'd him. How could she not, when she was face-to-face with him? It was a slam dunk. After some years in prison, the convicted person managed to get a DNA test, which proved he was not the rapist. How could this be? It turns out the DNA matched a convicted sex off…

This indicates that the jury/judge also failed the innocent man. What would have saved him? Are these cases relics before dna? Would it happen again today?

For better or worse, a huge amount of our justice system depends on eyewitness statements.

For example, if my crazy neighbour knocked on my door, pushed their way into my home when I answered then beat me up - the only evidence of who did it would be my eyewitness testimony.

There would be incontrovertible evidence that someone had assaulted me, in the form of my bruise-covered face and body. But only eyewitness testimony as to who.

With the current justice system, that would almost certainly be enough for a jury to convict.

There are tragic miscarriages of justice from time to time, and certainly DNA evidence should be used whenever possible. But would I prefer to live in a world which rejects eyewitness testimony, where a crazy person can barge into my house and beat me up with no consequences? Or a world where I have to have CCTV in my own home? Not really to be honest.

Re: Bad science and bad statistics in the courtroom convict innocent people

#60

Post by graphe »

klyrs wrote: post #51
graphe wrote: post #42

Earlier quoted context omitted.

You don’t just decide to lock someone up for a crime. Police gather evidence, give it to a prosecutor, the prosecutor makes a case (or not) and they will either go to trial or plea, then it’s in the hands of a jury or judge. Claiming guilt to plea down to avoid a case is a problem, but that isn’t the case you’re making. There’s nothing magical about criminal prosecution.

> If you’re looking for the criminal that killed a bunch of people but not that specific case it’s not that uncommon. Here you're saying that mass-murderers are common, but despite their extensive trails of corpses, we can't pin the actual crime on an actual criminal. No, there's nothing magical about criminal prosecution here, it's no more than bullshit as you've described it. Back to my question, why do you think m…

Blame laws like fruit of the poisoned tree. https://en.wikipedia.org/wiki/Fruit_of_the_poisonous_tree

If you want to act in bad faith and call it magic and bullshit feel free to grandstand.

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