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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

#221

Post by JoeAltmaier »

gamblor956 wrote: post #202
JoeAltmaier wrote: post #52

Earlier quoted context omitted.

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 te…

Testify does not equal independently certified. Also, double-blind testing is not really subject to faking. Its the standard of science.

Responses to my comment are all around 'how it is now' which seems not to be very reliable. A responsible testing/certification process would address that.

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

#222

Post by treeman79 »

irjustin wrote: post #94
tantalor wrote: post #29

Earlier quoted context omitted.

Why? The risk to their reputation & livelihood for a false positive should temper that.

A lot of DA and other prosecutors are measured by the number of convictions they get vs the number of cases they take to court. Their goals are always to get plea bargain because that is automatic guilt or if they take it to court, they'd better win. That's a lot of state resources just to lose. Overtime, you'll get people willing to bend the rules, turn a blind eye to 'weak evidence' or whatever. You're only as good…

Deal: Parole for a year. If not, full resources of the government to convict you, jail time in the decades. Evan a failure to convict can ruin you for life.

Even innocent people with a good alibi are going to take the deal.

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

#223

Post by gidan »

nickodell wrote: post #158
breck wrote: post #131

Earlier quoted context omitted.

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.

>My prediction: this firm will probably try to get removed from the case, rather than open source their shitty code. That isn't necessarily their choice. The prosecutors will make the decision about whether to withdraw the DNA evidence. They probably won't, given that they would need to give the defendant a new trial, which could lead to an accused murderer getting off. A bad look for any prosecutor. More to the poin…

That would be implying that the prosecutor would prefer taking the life of an innocent rather than having it hurt his career, making the prosecutor kind of a criminal.

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

#224

Post by JoeAltmaier »

kingkawn wrote: post #118
JoeAltmaier wrote: post #33

Earlier quoted context omitted.

While there have been cases of technicians guilty of systemic fudging of data, that is a tiny exception to the vast majority of honest technicians with self-respect.

Your sentimentality is not enough for a good justice system.

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.

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

#225

Post by jerf »

drdrey wrote: post #160
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?

There are countries where the job of the prosecutor is to uncover the truth, not to convict someone at all costs: https://en.wikipedia.org/wiki/Inquisitorial_system

I doubt there's any system in the world where it's officially the job of a prosecutor to "convict someone at all costs". It certainly isn't in the US. Nevertheless....

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

#226

Post by AnIdiotOnTheNet »

R0b0t1 wrote: post #148
AnIdiotOnTheNet wrote: post #87

Earlier quoted context omitted.

> 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.

It is possible that they could have well supported their assessment with evidence and still been wrong.

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

#227

Post by techolic »

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?

If it means what I think it means - understanding the code - sometimes it takes days to understand just one line of code. Document digging, googling, asking around, fiddling with test cases, reading production log etc.

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

#228

Post by Aachen »

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?

It depends on the level of scrutiny. It doesn't seem unreasonable. We review a lot more code per hour (usually C-like code though) but then we're not supposed to lock someone up for murder, we just find basic things like memory corruption. Don't even need to get into the business logic to find bugs that totally break the application, let alone all of it.

When writing Python (I don't have stats about reading), a 1.0 version of a small project took me 1.5 hours and consisted of 183 lines of code, so 2.2 lines per minute. That's much faster than this, but 183 lines is also a ton less complex than understanding the entirety of 180k lines and properly assessing whether it does exactly and only what it's supposed to.

10 lines per hour is probably taken as a lower bound to prove a point, especially because they argue about checking the whole thing (large parts can probably be skipped), but as a standalone statistic I would say it's probably within an order of magnitude from the true value. And for software time estimates that would be an amazing feat :p

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

#229

Post by kenjackson »

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.…

8 years is a long time. What he then wanted to code review Matlab, and then the compiler that Matlab used, then do some silicon verification...

Six to nine months seems like enough to do a very good code review with some testing. There's a good chance that 75% of that Matlab code doesn't execute for his test.

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