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Accused murderer wins right to check source code of DNA testing kit

theregister.com

31–40 of 520 posts

Re: Accused murderer wins right to check source code of DNA testing kit

#31
post #19

It's an important development. Forensic labs and companies are expert witnesses with black box processes and the incentive to protect the authority of their profession. They are as likely to lie as any other witness. Perhaps even moreso. "Those arguing on behalf of the defense cited past problems with other genetic testing software such as STRmix and FST (Forensic Statistical Tool). Defense expert witnesses Mats Heim…

> a forensic pathologist was giving fake prosecution evidence The doctor handled thousands of cases in his career, and a well-funded inquiry found issues with less than 1% of them. Sure we'd like that to be 0%, and society should spend time thinking of how much they rely on complicated processes of reasoning, but that's a really good accuracy.

You say that as if these were mistakes or unfortunate culminations of circumstance. The man committed fraud and sent innocent, grieving parents to prison by proxy. I don't think it's unreasonable to expect that to be 0.00% and punish those harshly who exceed that metric.

Re: Accused murderer wins right to check source code of DNA testing kit

#32
post #3

> Mark Perlin, is said to have argued against source code analysis by claiming that the program, consisting of 170,000 lines of MATLAB code, is so dense it would take eight and a half years to review at a rate of ten lines an hour. So it’s definitely riddled with bugs. And I can’t imagine that much matlab code following rigorous software engineering practices.

My exact thoughts. This sounds like a classic example of launching a prototype created by domain specialists (biostatisticians and bioinformaticians) as production software and skipping on the expensive stuff, like sound development practices

There is so little emphasis in production software development in bioinformatics and biostatistics. Despite a lot of groups open sourcing their code it's is nearly unusable and not reproducible due to hard coding, ignoring edge cases, and dumping the majority of the code on a single giant R or python function.

Re: Accused murderer wins right to check source code of DNA testing kit

#33

Earlier quoted context omitted.

> Forensic labs and companies are expert witnesses with black box processes and the incentive to protect the authority of their profession. I imagine they're also incentivised to favour a result indicating guilt.

Why? The risk to their reputation & livelihood for a false positive should temper that.

While there have been cases of technicians guilty of systemic fudging of data, that is a tiny exception to the vast majority of honest technicians with self-respect.

Re: Accused murderer wins right to check source code of DNA testing kit

#34

Wouldn't this set a precedent to eventually force any forensic software to become open source?

Not per-say, though it certainly affords it the same level of scrutiny.

Which may well be a win as open source already has that.

However, even open source has bugs that pass scrutiny as many CVE's can attest, so whilst a code review may find nothing wrong, that in itself could be used by a lawyer to create reasonable doubt, if the lawyer is good.

Re: Accused murderer wins right to check source code of DNA testing kit

#35
post #9
post #3

> Mark Perlin, is said to have argued against source code analysis by claiming that the program, consisting of 170,000 lines of MATLAB code, is so dense it would take eight and a half years to review at a rate of ten lines an hour. So it’s definitely riddled with bugs. And I can’t imagine that much matlab code following rigorous software engineering practices.

I also cant image anyone thinking that would be a winning legal argument... "This software is too complex to look at so just trust us" Really... that is what they went with...

Yeah, that's one of those "defenses" that feels like a confession.

Re: Accused murderer wins right to check source code of DNA testing kit

#36

Earlier quoted context omitted.

> Forensic labs and companies are expert witnesses with black box processes and the incentive to protect the authority of their profession. I imagine they're also incentivised to favour a result indicating guilt.

Why? The risk to their reputation & livelihood for a false positive should temper that.

Why should that come to light if the process is opaque? Most defendants don't have the resources to challenge that.

And if it comes to light, acknowledge a one-time error and carry on.

Re: Accused murderer wins right to check source code of DNA testing kit

#37

Earlier quoted context omitted.

> Forensic labs and companies are expert witnesses with black box processes and the incentive to protect the authority of their profession. I imagine they're also incentivised to favour a result indicating guilt.

Why? The risk to their reputation & livelihood for a false positive should temper that.

I seems like there are no repercussions for sending an innocent person to prison. I don't know if that's true, but it definitely seems like it.

Re: Accused murderer wins right to check source code of DNA testing kit

#38

Earlier quoted context omitted.

> Forensic labs and companies are expert witnesses with black box processes and the incentive to protect the authority of their profession. I imagine they're also incentivised to favour a result indicating guilt.

Why? The risk to their reputation & livelihood for a false positive should temper that.

The prosecution might call in a different expert in the next trial if the current one is not 'good'.

Re: Accused murderer wins right to check source code of DNA testing kit

#40
post #31
post #19

Earlier quoted context omitted.

> a forensic pathologist was giving fake prosecution evidence The doctor handled thousands of cases in his career, and a well-funded inquiry found issues with less than 1% of them. Sure we'd like that to be 0%, and society should spend time thinking of how much they rely on complicated processes of reasoning, but that's a really good accuracy.

You say that as if these were mistakes or unfortunate culminations of circumstance. The man committed fraud and sent innocent, grieving parents to prison by proxy. I don't think it's unreasonable to expect that to be 0.00% and punish those harshly who exceed that metric.

If I'm a juror, and the evidence presented happens to have a false positive rate of 1%, that certainly meets my understanding of "a reasonable doubt."
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