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Comment by JoeAltmaier | Hacker News Reader

I'm not so sure we should be allowing challenges to expert witness, with no evidence. That sounds like a rich source of abuse of the system, like a big company filing thousands of briefs to delay a case.

It's important for experts to use validated, tested equipment. That's clear. And by the sound of it that is happening (stories of how code was tested and found wanting confirm that; stories of double-blind testing).

Maybe what is needed is, an 'underwriters lab' certification for such devices. To forstal the inevitable gaming of the 'right to challenge'.

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defendants should always be able to challenge expert witnesses qualifications.

and how could anyone on hacker news claim there is 'no evidence' that unreviewed software may do something other than what people claim it does? especially if it 170,000 lines of matlab?

from the article:

> "Without scrutinizing its software's source code – a human-made set of instructions that may contain bugs, glitches, and defects – in the context of an adversarial system, no finding that it properly implements the underlying science could realistically be made," the ruling says.

Particularly when TrueAllele specializes in

>probabilistic genotyping [1]

and

>solves mixed DNA samples, low template DNA and kinship problems [1]

And the product sheet discusses

> models for PCR artifacts [2]

This sure feels like they go way beyond typical dna match technology into maximally extracting information via statistics, so their methods definitely should be open for review.

[1] https://www.cybgen.com/products/casework.shtml

[2] https://www.cybgen.com/solutions/brochures/unique_features.p...

In most criminal complaints the defendant has far fewer resources than then the prosecution. The prosecution has a conflict of interest to get a conviction. Absolutely everything about their process needs to be above reproach, including their experts. A challenge to that process, approved by a judge, seems like a small consolation in a biased system.

When I was a juror on a murder trial the one thing that was most clear was the disparity in resources.

On one side were 6 impeccably dressed men in what I presumed were multi-thousand dollar suits. On the other side was single overwhelmed, overworked, and under-dressed defender who was steam-rolled at every sentence she spoke.

I ended up in traffic court last year for a parking ticket that I can only think must have been stolen from my car during a festival. After spending just a few hours waiting my turn, it was pretty clear who exactly the police target for traffic violations. But this is a tangent.

Grossly oversimplifying it, but it is what my lawyer uncles say, and is consistent with what I saw as a juror on a civil trial involving many topics I'm personally an expert in, expert witnesses are paid to lie on the stand. At the very least they are paid very very well (the amount they were paid was emphasized at the trial I was at) to state only the information consistent with what the person paying them wanted to them to say, regardless of whether they know information that would be more helpful to the other side.

> At the very least they are paid very very well... to state only the information consistent with what the person paying them wanted to them to say

Anecdotally, if you replace 'paid' with 'incentivized' my understanding is the same.

And here's a totally unrelated Wikipedia link: https://en.wikipedia.org/wiki/Michael_Baden

Of course this is the case, but rather than lying, I think it is only a consequence of selection bias. You don't see the experts rejected by the prosecution (or defence) for opinions that aren't helpful, because of course they won't be invited to testify.

They answer any question put to them. The defense has to ask the right questions of course.

I know expert witnesses. They are of impeccable character, and will seek to educate as well as they are allowed.

The experience I had, which was pretty cool (although the case overall was very very depressing) in that we the jury were allowed to anonymously submit questions for the judge to ask the witnesses as well."They answer any question put to them." definitely did not apply to all of them. There were many, painful to watch, who at best gave half answers. I'd say the expert witness in the movie "my cousin Vinny" who testifies that the tire marks between the two cars are identical and that it is possible for both cars to have made the tire marks, while knowing that it was literally impossible for the defendants car to make the marks on the road, is very very close to what I saw experts do. In my case it was dumber, though. We had experts talking about how far a driver can see to recognize that a pedestrian is walking across a road and all of his citations were referencing daylight illumination. Thankfully, us jurors were able ask questions like "All of your citations are for daylight illumination. You know this case is about an accident at 3am and the streetlights were broken. What's the distance in that case?" And they would answer that question appropriately, but I didn't consider it impeccable character that they had acted all the while up to that point like the numbers they were giving were for the conditions of the case. And yes, they would always say they were familiar with the conditions of the case before answering any questions, so I generally felt is was lying by omission.

You know some expert witnesses. I doubt you have a good acquaintance of a significant percentage of all expert witnesses.

Absolutely not! Please, if you want to know why, look into expert witness testimony as a whole, possibly can start with “burn pattern experts”.

Not to mention we have a constitutional right (6th amendment) to face and cross examine witnesses against us in the US, a black box should not void that right.

When I was a public defender I made my career by cross-examining expert witnesses. There are a dozen innocent people walking around free today because I challenged the expert despite going into the cross "with no evidence."

What you call abuse, I call due process.

(And your proposed solution is already part of the expert certification and questioning process in criminal trials, so it isn't a solution. Experts must testify that the equipment they used was calibrated/certified/etc based on the standards applicable to the field.)

Testify does not equal independently certified. Also, double-blind testing is not really subject to faking. Its the standard of science.

Responses to my comment are all around 'how it is now' which seems not to be very reliable. A responsible testing/certification process would address that.

You've just moved the goal posts from someone who can be crossed in court to someone who can't, which is worse, because then you have now way of verifying that the "independent" certifier is actually independent or that the certification was properly done.

You still need to allow the "independent certification" to be examined in court to validate both the independence and the certification. The means testimony on the applicable standards, and how the specific equipment used satisfied those standards. And right now, the expert witness already does the latter with respect to calibration, etc., for the equipment they used.

The skepticism has to end somewhere. Else ever court case becomes an infinite regressing into doubting the foundations of everything.

Of course self-certification is not the best. To bring up that straw man (as most of these posts do) is not advancing the conversation.

Yes, the skepticism has to end somewhere. But when someone is facing years, or life, in prison, that skepticism absolutely should not end before it validates the primary evidence of guilt, and the tools used to purportedly analyze that evidence.

If you can't validate the equipment used to analyze the DNA, gunshot residue, or other scientific evidence, then that evidence should not be allowed in court, because that's prima facie reasonable doubt.

That straw man is essentially the status quo at the moment...

Reread the comment being responded to? It started with that, suggested an alternative. Anything helpful to add?

> I'm not so sure we should be allowing challenges to expert witness, with no evidence

Any challenge is "allowed" in the sense that the parties can try to convince the judge there is a flaw.

The question is one of burden of proof: should the expert prove they have a trustworthy result, or should the expert testimony stand on their credibility alone, and the defense scramble to poke holes into it armed with incomplete information.

For a system that can put people into jail for life and that acts as a direct extension of state power, it's obvious the latter can have disastrous consequences. Effectively, any one who acquirers the "judicial expert" title can put people in jail at their whim.

It seems reasonable to have a lower bar for challenging expert witnesses in criminal cases versus civil ones.

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