FBI testimony on hair analysis contained errors in 90% of cases (2015)

To be fair, any experiment investigating this could only show that they are evidence of arson. ;D

Evidence isn't there to _prove_ anything, else we wouldn't need to ask anyone to be a juror. That's why we use "preponderance of evidence" and "beyond reasonable doubt" as our metric.

It also assumes that all juries, once they see bite mark analysis, presume it's magic then simply decide they're going to convict at that moment and shut off their brains for the rest of the trial. Do people really believe this is something that happens?

> A 99% probability of innocence is probably about right in that part of the criminal prosecution decision tree.

I find it very difficult to believe there's a single piece of evidence in a trial that could convince anyone of this. The totality of the evidence is what must be considered.

A single test tells you about a single sample in isolation with respect to it's time and method of collection. It doesn't definitely prove anything about an event, and I'm astonished that you could see it that way; unless you're operating under the presumption that all District Attorneys are corrupt to the point of no longer caring about justice and truth.

There are certainly examples of corruption, but to presume it's the norm to the extent that a single piece of evidence presented in a particular fashion would cause you to turn _your_ back on justice and truth as a matter of rote course.

How is that an improvement?

Then why is there a difference between first degree murder and second degree murder? Murder warrants a particular sentence, and circumstances should not matter?

> But sentencing is based not on your crime

The court is taking into consideration your behavior and your reticence over your own actions. Taking the plea deal shows reticence as it immediately requires an admission of guilt.

Demanding a trial, particularly when you actually have committed the offense, in an effort to "get out" of the time you must serve or to merely publish your side of the story is not viewed favorably by the court. Why should it be?

You're tying up immense resources simply to parse the details of your crime in an effort to convince a judge that maybe you're actually not that bad of a guy. The court knows it is not a perfect arbiter of the truth, and that it's application of process inherently deprives, in some way, the rights of everyone involved. Every witness you call is subpoenaed to court under penalty if they don't comply. Victims are never actually made whole by the trial, and offenders run the risk of incriminating themselves further.

They're there because they're necessary, not because they are an ideal or preferred solution. Courts aim for settlements in civil trials, and they aim for pleas in criminal trials.

> were considered unconstitutional up until the 60s when the police/judicial state started undermining constitutional rights.

The means under which they were offered was unconstitutional, why should it be against the constitution for you to negotiate your own settlement in a criminal matter with the state? Is it really a better outcome that you must go to trial without any option?

> even when it was complete garbage like lie detector tests.

Lie detector tests actually _do_ measure physiological responses, though. The problem is that's not all they measure, and the results are too polluted by the reviewer to be useful. That a human beings heart rate increases when they intentionally try to deceive another is an actual fact.

So are they really "complete garbage?" Or are they just not as pure of a datapoint as we thought they were? Perhaps this is why some courts still allow them to be admitted when all parties agree to it's use.

This is not correct; they're supposed to e.g. dismiss charges if they learn they've charged the wrong guy.

The problem isn't that the system calls for them to convict innocent people. The problem is that they're evaluated by their conviction rate.

Or it shows a preference for 5 years over the risk of 15 years out of pure fear or knowledge that the jury will be manipulated with pseudo-scientific "evidence".

Taking a plea deal can be totally separate from guilt or innocence.

> You're tying up immense resources simply to parse the details of your crime in an effort to convince a judge that maybe you're actually not that bad of a guy.

You seem to be ignoring that someone may actually be innocent in some cases. You're sounding like an ambitious prosecutor yourself, or you just have too much faith that the system would never bring the wrong person to court.

> Courts aim for settlements in civil trials, and they aim for pleas in criminal trials.

Which, over time, turn into a perverse incentive structure because court time gets increasingly valued over justice and so plea deals become threats rather than offers.

Fundamentally, when presenting prosecutorial evidence that's not what it appears, my reaction, if I ever need to defend myself against such things, world be to further tie up the courts time by presenting evidence against the evidence and / or demanding a thorough explanation of the implications of what is being described as evidence. This could add literal weeks to every single case that goes to trial. The method of evidence collection would be on trial because there's so much trust lost due to, basically, lies on the part of law enforcement and prosecution in their pursuit of conviction as metric for success and promotion.