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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

#11

Post by Scandiravian »

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.

My exact thoughts. This sounds like a classic example of launching a prototype created by domain specialists (biostatisticians and bioinformaticians) as production software and skipping on the expensive stuff, like sound development practices

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

#12

Post by ChrisRR »

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/blog/archives/2009/05/software_prob...

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

#14

Post by avs733 »

syshum wrote: post #9
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.

I also cant image anyone thinking that would be a winning legal argument... "This software is too complex to look at so just trust us" Really... that is what they went with...

unfortunately, the technical illiteracy of much of the US judiciary has made this effective.

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

#15

Post by Scandiravian »

bryanrasmussen wrote: post #8
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.

and surprisingly all of the code is of equal importance so you really need to review each line sequentially! Instead of finding stuff that you think is most likely to relate to what you're trying to figure out and debug from there. Wow I would like to see this marvel of engineering myself!

Kind of makes me wonder: if the argument is that the code is too complex to review and understand, does that mean the company is not doing code reviews themselves?

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

#16

Post by MaxBarraclough »

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…

> 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.

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

#17

Post by michaelmior »

Scandiravian wrote: post #15
bryanrasmussen wrote: post #8

Earlier quoted context omitted.

and surprisingly all of the code is of equal importance so you really need to review each line sequentially! Instead of finding stuff that you think is most likely to relate to what you're trying to figure out and debug from there. Wow I would like to see this marvel of engineering myself!

Kind of makes me wonder: if the argument is that the code is too complex to review and understand, does that mean the company is not doing code reviews themselves?

If the code was developed in less than 8.5 years, it seems like the answer must be yes based on their previous claims.

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

#18

Post by gambiting »

michaelmior wrote: post #17
Scandiravian wrote: post #15

Earlier quoted context omitted.

Kind of makes me wonder: if the argument is that the code is too complex to review and understand, does that mean the company is not doing code reviews themselves?

If the code was developed in less than 8.5 years, it seems like the answer must be yes based on their previous claims.

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.

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

#19

Post by AS37 »

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…

> a forensic pathologist was giving fake prosecution evidence

The doctor handled thousands of cases in his career, and a well-funded inquiry found issues with less than 1% of them.

Sure we'd like that to be 0%, and society should spend time thinking of how much they rely on complicated processes of reasoning, but that's a really good accuracy.

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