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

theregister.com

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

#71

Post by dathinab »

yarcob wrote: post #48
AS37 wrote: 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.

From the Wikipedia page > In June 2005, the Chief Coroner of Ontario ordered a review of 44 autopsies carried out by Smith. Thirteen of these cases had resulted in criminal charges and convictions. The report was released in April 2007, indicating that there were substantial problems with 20 of the autopsies. That sounds more like 45% to me. Also this bit from the article about a baby that allegedly had a skull fract…

> there are gaps between skull plates.

Between Baby skull plates, not adult ones ;-)

They grow together at some point.

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

#72

Post by salamanderman »

JoeAltmaier wrote: post #52
motohagiography wrote: post #10

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…

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).…

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.

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

#73

Post by CivBase »

TheRealDunkirk wrote: post #41
zyngaro wrote: post #39

This kind of software should be required by law to be open source.

Yes, just like voting machines. But how do we confirm that the software which was vetted is the software that was actually _used_?

At some point you just have to trust people to not intentionally lie in a trial. We have very stiff penalties for anyone caught lying in court, but there isn't much more we can realistically do.

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

#75

Post by moron4hire »

ABeeSea wrote: 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.

That's like an accountant, accused of embezalling, refusing to hand over the ledgers because "there are just too many records to go through". Yeah-no, that's kind of the whole point. We want to find out what you've been hiding in that wall of paper.

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

#76

Post by dghlsakjg »

AS37 wrote: post #19
motohagiography wrote: post #10

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.

The end result of that tiny little error rate was tens of millions in settlements and legal costs, families permanently separated by government mandate, and multiple people spending more than a decade in prison.

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

#77

Post by linuxftw »

tantalor wrote: post #29
MaxBarraclough wrote: post #16

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.

Perhaps in a just society. Most places, the state and it's agents can do no wrong, there's almost no incentive to do the right thing.

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

#78

Post by pacamara619 »

TheRealDunkirk wrote: post #41
zyngaro wrote: post #39

This kind of software should be required by law to be open source.

Yes, just like voting machines. But how do we confirm that the software which was vetted is the software that was actually _used_?

It's not just like voting machines if it's just software. Just give it the same DNA as input and check if your results match the others.

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

#79

Post by dathinab »

ChrisRR wrote: post #12

This is similar to a case a few years back where someone asked to see the source code of a breathalyser that had found them guilty. AFAIR, the breathalyser was incorrectly averaging the readings, giving disproportional weight to the first reading. I don't know if it was enough to rule in their favour, but I'm sure it called the data into question Edit: Looks like it was a Draeger breathalyser https://www.schneier.com…

I wouldn't be surprised if "incorrectly averaging" and similar are very common software errors.

The reasons are manifold, including:

- Normalized values need to be averaged differently the absolute values.

- Floating point has limited precision, even just correctly summing/multiplying numbers need special care if you care about correctness. Results can, in the worst case, be of by a massive amount.

Often you don't need to care about it so it's not uncommon for especially junior programmers to be not so aware about it.

I mean in the last 3 years of working as a professional software engineer/developer I didn't need any of this at all, but once I do I know what to look out for.

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

#80

Post by Scandiravian »

gww wrote: post #32
Scandiravian wrote: post #11

Earlier quoted context omitted.

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.

That's my experience as well. My master's is in bioinformatics and I worked for several years in biotech.

I got frustrated because my concerns that my team's development practices were causing issues on a regular basis, were ignored. I was continuously able to predict what issues we would run into, but no-one seemed to care - I even had a manager tell me, that it was good that our software was buggy, since the client would continue paying us to fix it

I've since left the biotech industry. There's a limit to how many times I want to run my head against that particular wall

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