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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

#311

Post by JoeAltmaier »

tsimionescu wrote: post #287
JoeAltmaier wrote: post #224

Earlier quoted context omitted.

On the contrary, that's what the American justice system is entirely based upon. Fair judges, juries of peers and so on. Its the bedrock of justice. Engineers have some notion that it can all be replaced with science. In so far as science can certify the reliability of tests, that is good. But in the end one has to trust the humans between those tests and the courtroom.

The whole point of this discussion is that this trust is being largely misplaced. A lot of forensic science in itself is essentially phrenology (tooth prints, hair analysis - the non DNA kind, even fingerprinting is of exaggerated value). A lot of labs systematically turn out biased results with generally no expectation of risk, either personally to researchers and definitely not to higher ups. Ultimately, forensic e…

Yes there is a need for controls and independent certification.

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

#312

Post by fatnoah »

pvitz wrote: post #283
fatnoah wrote: post #277

Earlier quoted context omitted.

I wonder if bug tracker and other reports would be part of discovery in this case.

Equally interesting is in my opinion who should do the review. Mathworks' own consulting service is probably the best to do so, but I wonder if they would objectively work against one of their own customers.

Yeah, any technical expert in a trial concerns me. I was an alternate juror (meaning I had to sit through the trial but was not allowed to take part in any deliberations) in a trial that involved the testimony of a computer "expert". The expert's testimony was 100% true and appeared to definitely prove X to someone who knew nothing about the subject matter. It was things analogous to saying the system was secure because it had a security chip.

There were 1,000,000 questions I wished had been asked.

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

#313

Post by inetknght »

WaitWaitWha wrote: post #288

The tone of this thread is leaning to "forensics evil, government lackeys out to get the little guy". In the USA, all sides can call and rely on their own forensics. There is no government mandated & approved single-source-of-truth (with some minor exceptions). > Forensic labs and companies are expert witnesses with black box processes and the incentive to protect the authority of their profession. This statement is…

> There are no "black box processes". The very word "forensic" is based on presenting in full view, front of the fact finders (jury & judges usually).

You're wrong.

When the defendant can't afford an expert witness then the defendant is literally shut out from being able to understand the technology involved.

Good luck proving to a jury made up of non-technical people how thread timing problems cause math problems in DNA analysis without an expert witness.

Good luck getting an expert witness to testify to that when the source code is hidden behind a black box "company trade secret".

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

#314

Post by tsimionescu »

JoeAltmaier wrote: post #311
tsimionescu wrote: post #287

Earlier quoted context omitted.

The whole point of this discussion is that this trust is being largely misplaced. A lot of forensic science in itself is essentially phrenology (tooth prints, hair analysis - the non DNA kind, even fingerprinting is of exaggerated value). A lot of labs systematically turn out biased results with generally no expectation of risk, either personally to researchers and definitely not to higher ups. Ultimately, forensic e…

Yes there is a need for controls and independent certification.

There is also a need to recognize that a lot of this science just doesn't work (to the extent that it is often presented). The right way to phrase a lot of the conclusions of these experts, at the state of the art, would be 'in my expert opinion, it looks like it might be their DNA/fingerprint/hair/teeth', not 'in my expert opinion it is [...]'. Because even the state of the art is often about at that level - probably closer to 75% accuracy than 99.99% like it's often treated. Especially on real world, partial, corrupted samples.

And to emphasize again, I'm talking about the state of the art without the biases being discussed. The biases only compound this problem significantly.

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

#315

Post by maceurt »

phire wrote: post #93

> The co-founder of the company, 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. First, the defence doesn't necessarily have to evaluate all 170,000 lines. They just need to find one buggy line which could potentially overturn the result.…

It shouldn't take 10 lines an hour should it? I don't have experience reviewing professional code of this size, so please correct me if my assumption is wrong, but that number doesn't seem right.

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

#316

Post by knolan »

breck wrote: post #131
phire wrote: post #93

> The co-founder of the company, 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. First, the defence doesn't necessarily have to evaluate all 170,000 lines. They just need to find one buggy line which could potentially overturn the result.…

Lol. If it would take 8.5 yrs to review, it's probably god awful, and should never ever ever be used to convict someone of such a crime. My prediction: this firm will probably try to get removed from the case, rather than open source their shitty code. Source: I've worked on MATLAB codebases for various genomics research projects in the past.

170,000 lines of Matlab code for a project is not a good sign. Unless they’re also including the source of various Matlab toolboxes which are already tested by the Mathworks.

It’s such a high-level language it’s hard to imagine what the hell they’re doing with all that code. It’s probably mostly useless cruft from GUIDE.

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

#317

Post by deathlight »

ashtonkem wrote: post #199
flavius29663 wrote: post #150

Earlier quoted context omitted.

have you ever seen MATLAB code?

That’s actually a pretty good argument for banning such code from the criminal justice system. The idea that unreadable code is deciding who gets locked up is really worrying.

This thread makes me sad because when I was taught and used matlab we had strong pressures to properly comment and document our code to make it legible (if only to our own future selves). It feels almost criminal to not do that in these circumstances.

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

#318

Post by dingoegret »

WaitWaitWha wrote: post #288

The tone of this thread is leaning to "forensics evil, government lackeys out to get the little guy". In the USA, all sides can call and rely on their own forensics. There is no government mandated & approved single-source-of-truth (with some minor exceptions). > Forensic labs and companies are expert witnesses with black box processes and the incentive to protect the authority of their profession. This statement is…

That's because forensics has a sordid history of being overvalued in trial cases because of magic thinking like "it's science it must be the truth". When in reality a lot of it is quackery and science is the last thing that leads to a simple, quick and direct truth.

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

#319

Post by 0xfffafaCrash »

WaitWaitWha wrote: post #288

The tone of this thread is leaning to "forensics evil, government lackeys out to get the little guy". In the USA, all sides can call and rely on their own forensics. There is no government mandated & approved single-source-of-truth (with some minor exceptions). > Forensic labs and companies are expert witnesses with black box processes and the incentive to protect the authority of their profession. This statement is…

Sorry but forensic ”expertise” in the court room has always been laughable. In ”full view of the judge and jury” means absolutely nothing when these people are completely scientifically illiterate and defer to the so called expert who has a financial incentive to help the prosecutor. There’s an entire industry of people who make their livings by reliably testifying to the guilt of defendants and then being compensated for their “expertise.” They just need to be paraded as experts and how would a layperson be expected to know any better? The quality of defense in the American justice system has everything to do with who can afford to pay for it. I could cite a hundred sources but here’s a small sample...

[0] https://www.sciencemag.org/news/2016/03/reversing-legacy-jun...

[1] https://pubmed.ncbi.nlm.nih.gov/30447642/

[2] https://theconversation.com/how-corruption-in-forensic-scien...

[3] https://www.newyorker.com/magazine/2009/09/07/trial-by-fire

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

#320

Post by ncallaway »

sdflhasjd wrote: post #303
radu_floricica wrote: post #197

Earlier quoted context omitted.

And yet somehow whenever you take a closer look at mislabeled product prices, the average is always in favor of the store. And that's far from the only industry. Complex tools are the product of many thousands of individual decisions taken by humans, humans aware of who's the paying client.

I still believe Hanlons razor applies. I've seen products that have serious performance affecting bugs caused by similar mistakes.

I still think—even when applying Hanlon's razor—there's an imbalance in incentives that leads to a weight in favor of the interests of the party paying for the test.

Take the store pricing example. Suppose the store's pricing & labeling process produce an equal number of bugs at checkout in favor of the store and in opposition to the store.

The store is heavily incentivized to detect the errors that are opposed to them. They are much less likely to detect the errors in their favor. Consider the manager that looks at the cash at the end of the day and notices they are $500 short. They likely dig hard to find the root cause of the issue, detect the pricing disparity and correct it. Now consider the manager that is $500 over at the end of the day. They are much more likely to say: "that's weird", shrug their shoulders and move on.

The same applies to forensic tools. Even if they originally produced bugs in both directions, their own internal QA and the market of police officers are likely to work hard to detect bugs that make them less likely to allow them to make an arrest.

The net result is that the tools end up with a bias in one direction, even if the original developers made an equal number of mistakes in both directions.

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