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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

#201

Post by qwertox »

Here in Germany we have somewhat similar cases, but where the accusation is way less damaging than the case of this article, in which a false positive would have the drastic result of being labeled a murderer.

The cases are related to new speeding cameras which work with laser, where the defendants are complaining that these new devices are black boxes, and that they demand access to the raw data which these devices process. The problem is that these devices discard the raw data after having processed it and come to a conclusion that the driver was or was not speeding.

The devices in question are Traffistar S350 from Jenoptik and PoliScan SM1 from Vitronic.

There were discussions about a required software update which retains all this data, but apparently the devices lack the storage capability to do so. The National Metrology Institute of Germany (Physikalisch-Technische Bundesanstalt (PTB)) responded to this, that they would not re-certify these devices with updated software because from their point of view they work "as specified".

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

#202

Post by gamblor956 »

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).…

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.)

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

#203

Post by eptcyka »

bardworx wrote: post #164
Ma8ee wrote: post #149

Earlier quoted context omitted.

Of course prosecutors will favour expert witnesses that will help them get convictions. Why isn’t that obvious?

Ok, maybe I’m naive, but why is that obvious? Not arguing just trying to understand. My rationale is: prosecutors have to weigh an “easy” conviction vs the possibility that labs that always guarantee results may be biased. In the event that they get caught up with a biased lab, wouldn’t it look bad for their reputation? As in, they can’t even perform due diligence on their sources, how can you trust them in a promote…

Prosecutors don't seek justice, they seek a conviction.

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

#204

Post by Jolter »

themaninthedark wrote: post #159
curryst wrote: post #116

Earlier quoted context omitted.

> Compile it, run it with the same inputs the prosecution claims was provided, and see if you get the same result. That's sorta the point of computers, right? Same inputs on the same program, same output? One difficulty here is that the input is a real world effect. That means the answers are rarely exactly the same. The last time I looked, breathalyzers have a ~50% margin of error. So if you blow a 0.06, your BAC is…

> The whole thing, from top to bottom, is just a long chain of poorly aligned incentives. Field sobriety tests are even worse. The fact that your license can be revoked for refusing the test under the above grounds is nothing short of an end-run around the 4th amendment by declaring driving a "privilege, not a right" I agree and I wish I had a better solution. >They need to force people to go in for a blood draw to e…

Many jurisdictions would have enough cases come through to justify employing someone trained to draw a blood sample.

Btw here (Sweden) the breathalyzer is only used to help decide whether someone gets picked up for a blood draw or not. Only a blood test can be used to convict someone.

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

#205

Post by carlmr »

elliekelly wrote: post #22
Snoozus wrote: post #7

Why don't they just redo the analysis with a few other software packages?

The defendant has a right to “confront” their accuser. So when an algorithm is the one doing the accusing it seems only fair that the defendant should be able to understand how and why the algorithm arrived at that conclusion. Running the analysis through every software package available wouldn’t satisfy the defendant’s 6th amendment rights.

It wouldn't satisfy them, but if one of the software packages gave a different answer they can't both be correct.

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

#206

Post by roywiggins »

vmception wrote: post #134
zupreme wrote: post #60

What is unfortunate is that it took going to appeal to force the judge to allow the code review at all. Without, at minimum, an independent review (and preferably open source code) the software and lab processes being used constitute an inscrutable "black box" process within which any judgment can be made, for any conceivable reason, with life-changing effects for the defendant (and for the victims of a crime if, for…

People sometimes ask me what my “number” is, like how much net worth or “money” I want, what would I do with it I say “I want to be able to afford appeals court where my rights matter” Infinite appeals court! Most people plea out, cant make bail, dont have counsel buddy buddy with the judge enough to get you bail, and lose the ability to keep good counsel for more and more motions and appeals I want that, there is al…

Appeals? Only ~3% of people charged even go to trial, the rest plead out.

Just giving everyone a substantive right to trial would amount to a revolution.

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

#207

Post by fritzo »

scott00 wrote: post #102
steerablesafe wrote: post #30

Are forensic labs often get blind tested? If there is a bias for guilty cases then it should turn out in those blind tests. Source code is a red herring here, there should be independent evaluations of forensic laboratories/methodologies/etc... regardless of software source code availability. Maybe these checks are already in place, I genuinely don't know.

I don't know the answer to your question, but blind testing is complementary to (not a substitute for) source code review. It's very common for software to work correctly a high percentage of the time, but fail on rare input data. If, say, the software works correctly 999,999 times out of a million, you're going to be very unlikely to discover that error by throwing random samples at it, especially if you need a phys…

Agreed, blind testing is important for statistical correctness and code review is important to avoid adversarial backdoors like dieselgate.

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

#208

Post by IgorPartola »

IG_Semmelweiss wrote: post #182
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 think we can all agree that black boxes are not desirable. But let's not jump the gun here, and assume ill-intent.... to explain something that can be attributed to negligence, or simple human error.

When your negligence results in people wrongfully spending decades in prison I would argue that it ought to be criminal negligence. If your software does not produce results that are accurate, precise, and have confidence intervals included, how OK are you with people going to prison based on them?

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

#210

Post by Aachen »

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.

> 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.

It's not like you review all scientific evidence and re-do the experiments that lead up to the discovery of in the first place. Validating all that would also take years and much of it can be established as generally accepted by all parties. Similarly, there will be some trust involved with this source code as well. Getting the opportunity to look for bugs is essential in my opinion, but it needn't take multiple years. Focus on the parts you doubt, similar to what you'd do if you were reviewing the scientific method used in analog evidence.

Of course, the two aren't identical. Validating scientific methods and validating a program is different in that the program is proprietary and the science (usually) merely behind a paywall. The latter can then be replicated by others and becomes established. The former will only ever be seen by that company and doesn't become established. So scrutiny is necessary, but after a couple cases that used an identical version, requiring access without articulating particular doubts would unduly delay the case. It doesn't seem unreasonable to start trusting the program after a bunch of defendants had experts look at it and found no way to cast doubt on its result. If you don't think software of 180k lines can be used in court under such circumstances because it would take too long to review, we should throw out pretty much all software anywhere in the judicial system. (That's not what you said, but some of the replies including yours hint at that.)

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