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

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

#241

Post by bryanrasmussen »

agravier wrote: post #28
gambiting wrote: post #18

Earlier quoted context omitted.

Well I mean if something requires 8 man years of work you can do it in a year with 8 people. Not always, but usually.

On the contrary, such linear scaling would be quite exceptional. I'm speaking from experience but you don't need to trust me; I invite you read any book on software engineering management, starting from The Mythical Man-Month by Brooks.

the mythical man month was first published in 1975, I think the typical applications programmers work on today have changed significantly since then and encompass many different disciplines (to be thought professional) - so many disciplines that one developer is likely to be the master of all. It is true that there is a communication overhead to adding more people so it will not scale linearly, but if a single developer has taken 8 years to build something in our era it seems likely that having 8 people might get it done say 1 and a half to two years.

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

#242

Post by damagednoob »

fritzo wrote: post #188
damagednoob wrote: post #186

Earlier quoted context omitted.

How much uncertainty in the system are you willing to live with if you were falsely accused of murder?

That is a question for the judge or jury. The statistician's job is to provide a probability distribution, and to argue for the statistical correctness of that distribution based on similar inferences made on validation data.

In that case, at least with respect to the death penalty, "zero-defects" is precisely what the courts have moved towards.

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

#243

Post by undersuit »

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…

Guess you should just start doing these crucial DNA tests against some sort of panel of tests instead of just one lab. It would be a shame for the quality of the code in your one test to convict an innocent or free the guilty.

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

#244

Post by ChrisLomont »

carlmr wrote: post #194
wdobbels wrote: post #141

Earlier quoted context omitted.

If their argument is that their codebase is basically unreadable, then I see why they're scared someone might find some bugs here and there.

I'd get an expert witness in there to testify basically that. I also don't think you should code anything mission critical like this in Matlab. It's a decent language for prototyping, not for production.

The numerics in Matlab are far better than pretty much any developer can produce in production. This is why Matlab is used in production - it's vastly more reliable than people rebuilding the things it is good at by hand for bespoke solutions.

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

#245

Post by ncallaway »

kortilla wrote: post #81
MaxBarraclough wrote: post #67

Earlier quoted context omitted.

The hands-off reputation-based approach isn't enough to regulate food and drugs, or aviation. I don't see why for-profit forensics companies should be trusted implicitly. Also related: we know that funding bias [0] is a real problem in science, despite that scientists' reputations should (ideally) motivate them to resist such biases. [0] https://en.wikipedia.org/wiki/Funding_bias

No, the question is what is the incentive for lying and claiming guilty? Do prosecutors choose different labs?

You're a prosecutor. Your goal is to get convictions. You are objectively graded largely on your ability to secure convictions.

Every incentive you have leads you to preferring convictions.

You have a choice between two labs to hire for your field test. Lab A and Lab B.

Lab A gives you conclusive evidence leading to a conviction 95% of the time. Lab B gives you conclusive evidence leading to a conviction 65% of the time. Price and speed are roughly comparable between the labs. Which lab do you select?

---

You are now a lab director. You are under pressure to improve the sales of the lab's forensic services. You have pretty much maxed out making changes to improve price and speed, and have been matched by other labs. You understand very well the decision making process prosecutors will use to hire your lab.

---

The incentives clearly lead prosecutors to pursuing labs that deliver better results. Labs know this, and so are under market pressure to delivery convictions for prosecutors.

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

#246

Post by vlovich123 »

I'm curious. I've always been frustrated by this "closed" business model in the legal system. I feel like the entire process & details should be detailed in the open (code, methodology, controls, etc). Of course the counterpoint is that it makes it easier to copy this business & undercut all the time & energy spent on building it (copying is easier). Is that the only reason? I feel like open kimono is a critically important concept for anything related to the legal system because of how any perversion removes its legitimacy. If it really is that prohibitive to run a profitable business in this space, is there open standards that can be enforced (e.g. "this is the core algorithm that is approved" & businesses must get regular audits to continue to be used & any failed audit causes a reexamining of any court cases you were involved in the past year?). That's less ideal because then who audits the auditors but maybe at least it's an acceptable middle ground from where we are?

In general I've been extremely frustrated how regularly & consistently this entire industry keeps everything secretive & trust-based despite consistent examples of how insufficient trust is for this field & how devastating the results are when that trust is violated.

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

#247

Post by caconym_ »

IgorPartola wrote: post #208
IG_Semmelweiss wrote: post #182

Earlier quoted context omitted.

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?

Yeah, there need to be consequences for this. The alternative is empowering people and corporations to destroy lives with impunity in pursuit of their own goals, as long as they can later claim it wasn’t intentional.

What really pisses me off is how we fail again and again to ask the question of whether these entities should have been doing what they were doing in the first place, if it even can be done safely. Facebook, Equifax, police surveillance and misconduct, totally unaccountable “forensics” techniques—in all these cases where incalculable damage is done in totally predictable ways, we only address it reactively (if we address it at all) and completely fail to fix or even really consider the root cause(s). It’s like we have this huge blind spot where we take as a given that established entities doing thing(s) just have a right to keep doing them, regardless of any other factors.

In this case, forensics “experts” (essentially witch doctors) and fly-by-night black-box “labs” with unproven methodologies an undergrad intern might have developed in a week or two are institutionalized in our courts. This has happened because there is zero oversight and zero accountability for their claims, and lives are destroyed as a result.

It is insane not to pursue criminal charges for these indiscriminate arsonists of justice—if they can’t do what they claim to do fairly and accurately, they should not do it. They don’t have a right to “try” just because it will make them money, regardless of the consequences.

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

#248

Post by jdsalaro »

heavyset_go wrote: post #231
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.

They fill a similar role to prosecutors that field drug tests serve to cops[1]: they aren't meant to be accurate, they exist to give the cops legitimacy as they proceed to do whatever it is they wanted to do to you. In the cops' case, they need legitimacy to search and arrest you, and in the prosecutors' case, they need legitimacy to charge and convict you. If field drug tests were actually accurate, they wouldn't be…

> They fill a similar role to prosecutors that field drug tests serve to cops[1]: they aren't meant to be accurate, they exist to give the the cops legitimacy as they proceed to do whatever it is they wanted to do to you. In the cops' case, they need legitimacy to search and arrest you, and in the prosecutors' case, they need legitimacy to charge and convict you.

In case any of you are interested, or completely flabbergasted as I was, by the idea that law enforcement's purpose and raison d'etre could ever become as distorted and contorted as this comment mentions, you should definitely read more on Walter "Johnny D." Macmillan [1] or watch the movie based on his story: Just Mercy[2].

Absolutely mind-blowing stuff.

[1] https://en.wikipedia.org/wiki/Just_Mercy

[2] https://en.wikipedia.org/wiki/Walter_McMillian

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

#249

Post by HarryHirsch »

anonAndOn wrote: post #171
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.

> incentivised to favour a result indicating guilt Exhibit A: Annie Dookhan of the Massachusetts State Crime Lab who is suspected of falsifying thousands of drug tests [0] https://www.cbsnews.com/news/massachusetts-lab-tech-arrested...

Annie Dookhan did about 3 years of jail, which is risible, considering that her cooking of evidence affected > 30000 cases. No visible consequences for the supervisor, which is scandalous, considering that the had been carrying on for at least 4 years.

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

#250

Post by michaelt »

londons_explore wrote: post #198
michaelt wrote: post #176

Earlier quoted context omitted.

Unfortunately, the vast majority of crimes don't produce evidence that rises to the level you call for. After all, if my next door neighbour barged into my house and beat me up, the only evidence would be my visible injuries and my statement that it was my neighbour. I'm not sure if I'd prefer a society where he would be convicted, or where he wouldn't.

Maybe your neighbour has a nicer car than you which makes you feel insecure so you decide to beat yourself up and go to the police saying your neighbour did it. Considering that possibility, I don't want to put your neighbour in prison.

And presumably, if having been denied justice I pursue revenge instead, I can barge into his home and beat him up, as he did to me, and avoid punishment for the same reason?

While I admire your devotion to Blackstone's Ratio, this doesn't seem like a recipe for stability and rule of law to me.

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