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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

#141

Post by wdobbels »

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.…

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.

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

#142

Post by Spivak »

mseidl wrote: post #132
TheRealDunkirk wrote: post #41

Earlier quoted context omitted.

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

Nobody should use electronic voting.

People keep saying that but electronic voting would be great! Set it up so the process is exactly like mail-in ballots except digital and you can’t have made it any worse. It’s not like emailing a PDF to be opened by an election official is any different than mailing a document to be opened by that same official.

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

#143

Post by boomboomsubban »

geocar wrote: post #88
kortilla wrote: post #81

Earlier quoted context omitted.

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

If you knew someone was guilty, because of a preponderance of other evidence you have the utmost faith in, such as a professional law enforcement officers’ eyewitness account, and the DNA testing vendor you were evaluating said “not guilty”, what exactly would you expect to happen?

That the eyewitness account would be discarded, they make for terrible evidence anyway.

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

#144

Post by partyboat1586 »

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.

>170,000 lines of MATLAB code

This is a deep problem. Many scientists don't understand software engineering and more and more need to write bigger and bigger programs. And most of the time they don't open source their code.

Open source science.

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

#145

Post by sdflhasjd »

text70 wrote: post #90
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…

A tool designed to find people guilty is biased to find people guilty. As far as I know it is fairly easy to take a generic dna sequencer meant for healtcare diagnostics, and repurpose it for STR analysis. The only major difference between the healthcare versions and the forensic versions is the software i/o.

> A tool designed to find people guilty is biased to find people guilty.

I don't see those particular issues make it biased, just inaccurate - it could go either way.

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

#147

Post by merpnderp »

thgaway17 wrote: post #122
pelliphant wrote: post #92

Earlier quoted context omitted.

That seems plausible. I would argue that if prosecutors and/or cops get to pick the tool, false positives would result in more sales. Just as false negatives would result in more sales if the defendant gets to make the pick.

false positives would result in more sales. That seems highly unlikely. Prosecutors, like all attorneys, talk. It wouldn’t take too many getting burned by a false positive before word would get out (regardless of any nda). For example, once an expert gets Dauberted, you’ve got to think long and hard about being the next guy to use them.

But genetic evidence is often enough to convict by itself. A false positive is far more likely to land a conviction than an embarrassment to the prosecutor. I mean we live in a world where DNA evidence will easily override solid alibis.

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

#148

Post by R0b0t1 »

AnIdiotOnTheNet wrote: post #87
yarcob wrote: post #48

Earlier quoted context omitted.

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…

> Holy shit that is bad. Even as a lay person I know that there are gaps between skull plates. Sure, but can you tell them apart from a fracture caused by injury? Presumably someone knowledgeable in medicine should be able to, but maybe it is one of those things that isn't as obvious as we, the uneducated outsider, might think.

That's an extremely flawed argument. If you can't explain it to a layman then you don't understand it. If you can't tell whether it's a gap or a fracture -- you can't get a conviction.

"It just looks like it" is not a valid reason.

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

#149

Post by Ma8ee »

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?

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

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

#150

Post by flavius29663 »

abfan1127 wrote: post #120
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.…

10 lines per hour? doesn't that seem painfully slow?

have you ever seen MATLAB code?
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