Hacker Newsnew | past | comments | ask | show | jobs | submitlogin
Open-source DNA website GEDmatch helped crack Golden State Killer case (mercurynews.com)
67 points by nl on April 27, 2018 | hide | past | favorite | 40 comments


> “If you require absolute security, please do not upload your data to GEDmatch. If you have already uploaded it, please delete it,” it continues.

While I have no problem with GEDmatch, this sort of misses the point. Yes, if you're a serial killer and rapist from the 1980s who left behind a trail of DNA evidence, by all means, don't upload your genome. However, what if your cousin uploads his?


I know that we're pretty pro-privacy around here, but I'm gonna just go ahead and suggest that everyone not rape or kill someone.


The issue with this use of technology is it creates an air of science to investigating large groups of people.

It's easy to imagine a world where if they find someone that's likely a first (or second!) cousin of a rapist, that they then surveil the entire family and use that as evidence for warrants or other investigative tactics. In this case they cross referenced the familial identification with other factors, but imagine if they hadn't? They might have put a tail on everyone who shares a common grandparent or great-grandparent.


How high should the bar be for doing some surveillance?


Legally: This depends on the type of surveillance. Reading someone's first class mail requires a warrant. Posting a car on public streets to observe them requires nothing.

Ethically: law enforcement finds most violations of the law in places they look, so if it's unfair where they're looking, it's easy for that to translate into unfair outcomes. A society where police are watching every Capulet but not investigating the Montagues is one where most of the arrests will be of Capulets, regardless of who is actually committing crimes.

Therefore, when talking in populations, surveillance approximates punishment and familial surveillance approximates collective punishment of an extended family.


The problem is not for the rapist or killer, the problem is for someone innocent getting matched as one.

If you run a 99.99% accurate match against a database with 100,000 people, one of whom is the criminal, you are going to get 10 false positives.

If you're one of those false positives, good luck convincing a jury that the 99.99% accurate test is wrong in your case. There's a reason for why general warrants, and most kinds of fishing expeditions are illegal.


This procedure was used to identify leads, not conclusively prove someone was the killer. For that, they use DNA from the suspect himself.

In this case, an man in Oregon was earlier a suspect, but direct DNA comparison ruled him out.


The prosecution has this mans DNA. His relative's DNA likely matched a lot of people. Obviously, they didn't arrest the entire family. It seems likely that they will collect his DNA and attempt to match it to the DNA in his semen. If they get a match, then there is a high likelihood he is the suspect.

More likely, though, they will get a full confession. Serial killers often love to explain their work and take a lot of pride in confessing, because they're really messed up people.


parent is talking about the false positive cases - not the actual matches..


DNA evidence is often collected from fingerprints and it has been shown in many experiments that people can pick up and deposit DNA from other people.

As a result your DNA can be found at a location you have never been to.

If DNA evidence is being used to narrow down a small group of suspects this is less of a problem than if you are searching a population scale group.


> As a result your DNA can be found at a location you have never been to.

Sure, but how could it possibly be linked to you?


https://www.themarshallproject.org/2018/04/19/framed-for-mur...

You already exist in a criminal database, comes up as a hit, police create a narrative to fit it, even though it is a false narrative.


Through the implication of samples collected from others, at locations you have never been to.


How could that be linked to you? Suppose my DNA is on the person I brushed on the street today. How would a government agent be able to prove that whatever DNA they extract from his coat sleeve is mine? In order to do so, they would have to have a sample of my own DNA. It is unlikely a judge would sign a warrant for my DNA, given that I am not even suspected of any crime.

You argue that a judge could issue a warrant on an innocent person. However, warrants are only issued if there is enough plausibility that a person could be guilty of a crime. At the point the warrant is issued, the government can now force you to give your DNA. But that could happen right now.

Ultimately, in this case, the FBI barely exercised any of their authority. They didn't do any backroom dealings or use 'secret' laws. They just signed up to a genealogy website where people freely share their DNA information with the DNA sample voluntarily given to them by a rapist and murderer. The rapist has no right to any kind of privacy after giving his DNA away. Moreover, no one has any right to prevent a person who shares their genetic information from not disclosing it.


> How would a government agent be able to prove that whatever DNA they extract from his coat sleeve is mine?

Because your cousin was arrested in 1999 for burglary and held for 30 hours until they realized they had the wrong guy.


You can easily get somebody's DNA without their explicit consent btw. Just go through their trash.


> Suppose my DNA is on the person I brushed on the street today. How would a government agent be able to prove that whatever DNA they extract from his coat sleeve is mine? In order to do so, they would have to have a sample of my own DNA.

That is exactly what the article is about: using large genetic databases to find DNA they have never collected in connection to an investigation.


They never collected the rapist's family's DNA. All the FBI has ever had access to was the rapists DNA (from his semen). They matched it using a service that his relative opted into. The rapist has no right to control relative's DNA.


And I believe it wasn't even a close relative. DNA matching can identify relatives many generations separated from someone, by finding stretches of DNA with the same set of specific mutations (haplotype) that have not yet been broken by recombination.

What this means is that getting just a small fraction of the population into this database will enable it to provide leads for any DNA sample.


> The rapist has no right to any kind of privacy after giving his DNA away.

Umm...

The person who shared their DNA was neither a rapist or murderer but was simply related to one.


Right... but how did they have anything to match it too? They have the rapists DNA because he left his semen in the women he raped.


There is a chance, admittedly probably not a good one, that my DNA could be in a database associated with a rape or murder. Maybe yours might be as well. When I was in high school, I found a bit of cloth in the woods. No idea where it came from. But it got used to clean up after some coital fun and then discarded (I think in a parking garage?). Who knows where it eventually landed and whether it was taken as concrete physical evidence of my involvement in something? If only not being found guilty of things was as easy as not hurting anyone...


Your statement doesnt make sense. as a male, you are naturally capable of rape.


But a lot of us like freedom and democracy. And given than my grandpa stilll has a number tatooed on his wrist, I really wish people would start taking human database as a threat. The potential for abuse is way too great to be ignored.


Suppose you have been in/next to significant number of places of serial... criminal act. And you sneezed at each place. Or, like me, you have a condition that make you shed excessive skin. Or both.

Chances are your DNA would be at each site in a significant amount and you may be amongst several people linked to all cases. Chances are that you being in all these places is not a coincidence but you have a motive to be there - be it a work or something else. You can be tied to these places in some other way.

If your cousin let this DNA DB shows his DNA and police can relate these, you are... you will have some interesting time with the justice system.


How could the government get their hands on your DNA, unless you've committed some crime in which your bodily fluids were involved?

> However, what if your cousin uploads his?

If you've given your DNA freely to the government by participating in a violent crime, then hopefully you will be caught and your cousin will be relieved that yet another criminal will face justice.



Link [0]: voluntarily given samples. There is an issue with stop and frisk, but it has to do with warrantless search. This was an issue before this case, and will still be an issue. It is a separate issue. Nevertheless, in this rapists' case, no evidence was collected by warrantles searches. All evidence was freely submitted.

Link [1]: Again, this has to do with forced seizures. These are actually wrong, independent of any DNA collected. Nevertheless, the government did not do any of that here.

Link [2]: The police claim to have pulled the man over because of probable cause. They have a right to do this. They collected a cigar from his car. I'm not certain of the legality of this, tbh. But as to the legality of pulling over a car suspected of speeding? I'm pretty sure that's legal.

Look, I find government overreach to be a major problem. But this is not a case of government overreach. There was no warrantless anything in this case.

The relative of the rapist has no standing to sue the FBI in court for wrongful use of their information, because they freely provided it to a website. In all the cases you listed, the people (in my opinion) should have a right to have cases dismissed because this information was collected illegally.


> If you've given your DNA freely to the government by participating in a violent crime

Ignoring the intentionally bizarre phrasing ("if you've freely stoned yourself to death by committing adultery"), this is unrelated to the actual situation, which forces people arrested for a felony to surrender their DNA.

1) Both not restricted to "violent" crimes and not including all violent crimes, and

2) not requiring a conviction, or charges to be pressed.


I'm not sure how you're comparing adultery to rape.

When a man rapes a woman, he typically leaves behind his own DNA in the form of semen. That DNA is the only DNA the government has access to.

Contrary to what everyone here is saying, the government does not have access to the relative's DNA at all.

The phrasing was not intentionally bizarre. If you rape someone, then you consent to have your DNA examined by authorities so that they can catch you and put you in jail.

The irony in having to defend the idea of needing consent from a rapist has apparently escaped Hacker News's hive mind.


In the case of the serial killer, they got a match through the suspect’s relatives’ DNA and filtering for age and location.

Then they went through the suspect’s trash to get an item with his DNA on it.


You have no recourse then.


Or, more to the point, not one single person has any recourse, whether they're an evil serial killer/rapist or not.

But, I'm trying to think about a situation where a secret identity might leave behind trace evidence that could be linked to a readily identifiable relative's samples, thus unmasking... say Spiderman.

I guess, any situation involving trespassing or physical presence under other circumstances, where a person might leave behind a single hair follicle, including the root of the strand.


Definitely. As the number of sequenced individuals grows, it'll become that much harder to hide from a familial genetic search.


In what way is GEDmatch "open source"?

It looks like it's free as in beer, but I don't see any reference to source code.


This one: https://en.wikipedia.org/wiki/Open-source_intelligence

It's (relatively) public information.

I'm just pointing out the usage is common, I'm not interested in arguing about it.


Ah, I'd forgotten about that usage. Thanks, that does make a little more sense.


I suspect that this technique has been previously used, but was only disclosed in this case to widen the Overton window on police use of DNA on a case that everyone agrees was worth solving.


The concern being expressed about this is absurd.

The database was used to find leads (by finding people who shared segments of DNA with the killer, indicating some family relationship), but was not used to conclusively determine the killer. That was done with samples from the criminal himself.

My reaction on seeing this is "Great! Where can I upload my DNA information on the off chance I can also help find a monster like this?"


I feel sorry for those victims




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: