Dutch Cold Case Murder Solved After 8000 People Gave Their DNA

sciencewatcher writes "A 1999 cold case rape and murder in The Netherlands has been solved. Dutch police asked 8000+ men living within 5 kilometers of the crime scene to volunteer their DNA so that the murderer could be traced through (close or distant) family members sharing part of this DNA. As it turned out, the man now in custody turned in his own DNA, resulting in a 100% match. The request of the police was discussed here on Slashdot in September. The percentage of people participating was closing in on 90%; in the midsize town of the victim it was 96%."

Comments

Interesting

[MyLongNickName]

It is interesting to see the different attitudes toward volunteering information to the government. If NYC asked something like this, it would be an outrage and participation would be roughly 1% if it moved forward at all.

Re:Interesting

[Anonymous Coward]

Lucky to get 1% before the ACLU (Or some other group) files suit to block

Re:Interesting

[Anonymous Coward]

"volunteering"...?

"You can volunteer your DNA to eliminate yourself as a suspect, and eliminate the need of SWAT kicking down your door to get the DNA."

Re:Interesting

[Anonymous Coward]

I don't know about their government but what I do know is that our government would store that DNA data forever. Not only that but they would share this DNA data with anyone, possibly including Insurance companies, and private corporations. Finally the last straw is that even if they don't just give the data away they will not take any consideration to secure the data.

This is why we don't want the NYC government getting the data.

Re:Interesting

[poetmatt]

actually, no - it's interesting to see what actual happens, because the question is - how/why does this DNA match actually matter?

It's nearly as impossible to associate DNA at a crime scene with an individual being actually involved without further proof - otherwise this is in the same category as trying to assign an IP address to an individual.

Re:Interesting

[readin]

I find this method seriously scary due to the probability of a false positive. I mean, suppose you have a system that only fails once in a million times and the killer has already left the country. You ask the two million people in the metropolitan area to submit DNA. You get on average two matches. One doesn't have an alibi. You take him to trial and tell the jury that he not only doesn't have an alibi, he had a 1 in a million DNA match. It sounds pretty convincing. It is very possible the jury won't have the understanding of statistics to ask "was this a sweep or did you only test a couple of likely suspects?" Nor is it likely that the information will be volunteered by the court.

Re:Interesting

[interkin3tic]

I would hope so. It could be that one "success" of volunteer submissions could pave the way to some lawmaker suggesting it be "encouraged." Then outright mandatory. I'd rather err on the side of having murders and rapes go unsolved, rather than err on the side of police having everyone's DNA sequences.

Re:Interesting

[westlake]

It is interesting to see the different attitudes toward volunteering information to the government. If NYC asked something like this, it would be an outrage and participation would be roughly 1% if it moved forward at all.

Have you any evidence to support that assertion or do you simply think that these are the words the geek wants to hear?

Re:Interesting

[Anonymous Coward]

Except the birthday paradox doesn't apply. You aren't trying to figure out if a group exists where some set of two people have similar DNA. You instead have a fixed set of DNA that you are comparing to each and every other person in the group. Big difference.

Re:Interesting

[Anonymous Coward]

The would be cool if they sequenced all the dna for comparison, but they don't. They look for specific markers that can actually be alike in unrelated people. A small chance, but not zero.

Re:Interesting

[Vintermann]

A confession should not be the end of the story. An instructive case in the news these days is the story of Sture Bergwall, better known under his serial killer name Thomas Quick. It turns out he likely didn't kill a single person - he was just a disturbed drug addict who made up stories (mostly under the influence of strong sedatives and "repressed memory therapy") to fit unsolved cases. They glossed over his inaccuracies, contradictions and the total lack of evidence in case after case, year after year.

(An interesting bit is that Bergwall's defender was the lawyer/politician Claes Borgstöm, who's currently infamous for pursuing Julian Assange. If he had done any due dilligence at all, he must have suspected something was amiss. You got to wonder if there was something in his ideology which caused that gross failure.)

A lot of people, who aren't so smart and are aware of it, tend to be totally dominated by supposedly scienfific authorities. If the authority says it's absolutely certain you did it, they would rather doubt their own recall than the authority.

Re:Interesting

[yabos]

Then if they are really interested in you, they can get a warrant. Stand up for your rights.

Re:Interesting

[Pete (big-pete)]

In a room of about 20 people you have a 50/50 chance of having the same birthday as someone else in the room.

No, no, no, no, no! In a room of about 20 people there is a 50/50 chance of having two people with the same birthday. This is absolutely different of you having the same birthday as someone else, which is about 5.5% chance.

-- Pete.

Re:Interesting

[jiriw]

No... People want to have a murder solved. There is a difference. And if you can't trust your government then you live in a very sorry nation indeed.

The hard part is voting the right people in to be your political leaders. Now I don't say everything is all shiny here in the Netherlands because it isn't. But at least we know we can vote every four years and have a choice of political parties to choose from who are actually -different-. And that an absolute majority is a herculean task to achieve so we always have coalitions. Which is good because it means politics has to care about minorities. So, next time you go to the voting box (if you actually do live in the Netherlands), do not vote for the party(/ies) that try to relax the privacy laws so you can actually put a little trust into the government for not randomly trying to fuck you up.

By the way, just in: nu.nl. The second, minute DNA test (which took 6 hours to perform) also identifies the suspect as the one matching the traces both on the victims body and the lighter found at the scene of the crime.

Re:Interesting

[SecurityGuy]

You are wrong. They don't sequence and compare your entire genome.

Re:Interesting

[nedlohs]

They don't do a "full scan", the marker matches is it. Crime scene samples are contaminated anyway so you aren't getting a "full scan" out of it in the first place.

In the case of "we suspect X due to this evidence, test his DNS for a match" then a match to enough markers would be very good evidence - it's very unlikely he would match by chance. But doing it the other way "compare all these samples against this one" gives you a much higher chance of a random match. 8000 isn't that high a number though - assuming they had a lot of markers. It's still a terrible way to use DNA evidence - and you can be pretty sure they won't tell the jury about the actual odds of a random match in a multi-sample comparison and instead just use the 1:1 match odds.

Re:Interesting

[operagost]

No government should be trusted. Ever. If you trust your government, you will be a sorry nation indeed.

Re:Interesting

[QuasiSteve]

It's interesting to see this guy come forward, you can google dna testing and figure out what's going on. If he was indeed the killer he could've voluntarily declined, like I'm sure some people did.

People did, both in this test, and the previous test. I don't think they've mentioned whether this suspect had also had a DNA sample taken the first time around.

Here's the thing about this second set of tests. They weren't specifically looking for a direct match with the perp (though that ending up being the case is, I'm sure, a boon) but rather for a match to a family member of the perp.

So assume the first time around he declined to let a DNA sample be taken, and gets to walk scott free.

But this second time around, his sons who actually knew the victim at the time, may or may not be tested against. Being the father of them, he could either take that risk and hope they did not get tested against... or also supply a sample to spare his sons the additional shame, guilt, etc. of effectively having ousted their very own father by virtue of the lab having a direct match.

That would be my guess as to any reason for coming forward, at least. Who knows, maybe he just started feeling guilty, grew a conscience, etc. and the above is unrelated.

Re:Interesting

[vertigovegan]

You should find it scary. The odds of a false positive are probably much higher.

The DNA database in the US has found matches between a black man and a white man if you point it at itself. They only look at about 12 spots and sometimes use just 9 to identify someone.

"903 pairs of profiles matching at nine or more loci in a database of about 220,000. ...State officials obtained a court order to prevent distribution of the results."

http://news.lawreader.com/2008/07/22/dna-match-between-two-men-raises-question-about-validity-of-dna-tests%E2%80%A6fbi-seeks-to-block-inquiry/
http://www.deathpenaltyinfo.org/accuracy-dna-matches-definitively-identify-suspects-questioned

Re:Interesting

[dbet]

That's because NYC would keep your DNA on file forever, and use it to bust you for things that aren't even crimes, like protesting.

Re:Interesting

[Johann Lau]

if you can't trust your government then you live in a very sorry nation indeed.

Wow. In what nation do you live, pray tell? Did they achieve this remarkable success just by fooling you, or were you outright re-educated?

The hard part is voting the right people in to be your political leaders.

LOLNOPE.

The hard part is that you vote based on promises, and those people are not at all bound by that promise, or your vote. Once they're voted in they can do whatever, including the opposite of what they promised. While it's illegal to put up a fake vending machine (which promises X, but only gives you something else, or even nothing, after you inserted money), there are no such qualms with politicians, and certainly no laws, not to mention enforcement of them, regulating politicians and their false promises.

You can only trust *anything* it in so far as you can influence it, and/or in so far as it loves you. No such dice with governments usually. So unless your country radically differs from this, if you trust the government, you're being silly. And even if it does, even if *you* can trust *your* government, because it's really special that way, then the easiest way to loose that is to look down your nose at people who are making different experiences with theirs, and taking the fact that you're not raped and thrown away for granted.

Re:Interesting

[jiriw]

The devil is in the details. I don't say you HAVE to trust your government, just that it's sorry IF you CAN'T trust the government. But then, maybe this is all because of cultural differences and we'll never agree.

Now, in what world would you live if you actually COULD trust the government to do good things and they would? Or if you knew that when they did wrong it could be amended just by a proper re-vote instead of having to implement drastic measures like carving the right to bear arms into a constitution which will fly out of the window anyway if a government really wants to implement evil... and in the mean time will inflict all kinds of harm to society. (Excuse me if I'm uninformed but I regularly read about all kinds of nasties happening over the pond, like public place mass murders, children having gun accidents, increased rates of crimes with lethal consequences etc. Here those things are... drastically less frequent.) Of course, it's your nation.. your peoples decisions. Not wanting to lecture here but please do allow me to find things odd, as you do about us.

Think about it.

Now, mod me into oblivion if you're a true patriot. I'm nothing of the sort. But I am someone willing to trust until someone shatters it... within common sense of course. I'm not that much willing to hand over advance fees to Nigerian princes.

Re:Interesting

[Capt.DrumkenBum]

I'd rather err on the side of having murders and rapes go unsolved, rather than err on the side of police having everyone's DNA sequences.

Why? Not trolling, but it seems to me that if everyone's DNA were on record the crime rates would drop through the floor.
Maybe I feel this way because a good friend of mine was raped a few years ago, and if all DNA were recorded the asshole who did that to her would probably be rotting in jail right now.

Re:Interesting

[mariox19]

There is no end to the amount of crimes that could be prevented or solved if only we were ready to embrace draconian governmental invasions of our privacy and restrictions on our freedom of choice. Do you realize that if we only had laws forbidding women from traveling alone in public without being escorted by a male relative how many rapes we might prevent each year?

Re:Interesting

[TheRealGrogan]

I am very suspicious about this. Why would he submit a sample if he is the one who did it? This is probably all bollocks and the man is innocent.

I would never submit my DNA in that manner. If that made me the odd man out, implying guilt because I won't cooperate, so be it. If they go and take a sample by whatever means, it wouldn't be admissible anyway.

This is like a witch hunt.

Re:Interesting

[viperidaenz]

zero involving close family members. Those ones would probably increase dramatically.

Re:Interesting

[dingen]

The fact they're even asking for DNA again is evidence in itself they actually do destroy the material.

They already asked about 20.000 people for their DNA in 2000. They wanted to test again now, because recent developments in both technology and legalization have made it possible to search for family relations as well in the found DNA material from the crime scene. They couldn't use any of the material they gathered in the previous investigation for this new test, because it was all destroyed.

Re:Interesting

[interkin3tic]

Because I'd rather keep what we have: a state where there may be higher incidences of rape and murder, than a state where the government has my DNA on file. Murder and rape can always be countered effectively by methods we have now. And if crime gets too bad, it's not too hard to turn that situation around. Erosion of privacy, and police state on the other hand are situations that are pretty much permanent. You can always put more cops on the street and be careful if you're worried about getting shot. Law enforcement with too much power on the other hand pretty much requires moving to a different country, or a revolution.

Re:Interesting

[cheater512]

Erm they do essentially take a hash.

Do you really think when you do a police DNA check that they sequence your entire genome?
That costs tens of thousands of dollars. No they do a much simpler test.

It is simply a human barcode.

Re:Interesting

[JaredOfEuropa]

You're kidding, right? Our (Dutch) minister of justice recently suggested it might be a good idea to use DNA gathered and stored for research (with the donors being told that it would be used for that specific reason alone) for criminal investigations like this one as well.

The problem with Dutch politicians (especially with the current government) is that they often are very practical. Which is great if you want to get something fixed. The problem lies in the fact that they forget or ignore base principles in the process. To them, civil rights are not a boundary not to be crossed, but merely an impediment to getting results, and always up for negotiation.

Re:Interesting

[Macgrrl]

Not trolling, but it seems to me that if everyone's DNA were on record the crime rates would drop through the floor.

You'd think so, wouldn't you. But if you read the summary, the guy in question volunteered his own DNA which came back as a 100% match. Most criminals aren't that smart. They frequently believe they won't get caught - if they even think about it at all.

Having sentencing that is intended to be a deterrent - up to and including the death sentence in some states - doesn't stop people from trying to get away with murder.

People committing assault/rape/murder are rarely thinking with their rational brain when they commit the crime.

Re:Interesting

[Pseudonym]

Erm they do essentially take a hash.

No. They look for 13 specific short tandem repeat loci which are known to have fairly good discriminating power.

Re:Interesting

[mariox19]

Your arguments are silly. No one is forced to use credit cards; besides, what are banks going to do with records of your purchases, develop a consumer profile and try to sell you things? No one is forced to join Facebook, and even if they do, you're not forced to share anything you don't want to. Red lights and speed limits are a nonsense argument. As to speed cameras, I and plenty of other people do complain about them, for various reasons. As to shop owners and their CCTV cameras, these are decentralized.

The argument you make is either completely ignorant or you have some kind of hard-on for government. We don't know what the full extent of knowledge about one's DNA will mean, and it's wise to keep it private. Moreover, innocent people shouldn't be bothered as a matter of policy, no matter how "helpful" that is to police work. We don't live for the police or government; they live for us.

It's you who is "mindless," with all your talk of "we" when talking about government. Government is like a gun. It's a great thing to have when it comes to protection, but you don't leave it lying around and you don't let it fall into the wrong hands. Allowing government every type of intrusive "convenience" is the fastest way to put together turnkey totalitarianism. It's bad civic hygiene.

Take your servile mentality somewhere else.

Sounds improbable

[dinfinity]

"As it turned out, the man now in custody turned in his own DNA, resulting in a 100% match."

If he was really the guy who did it: Was he wondering whether the DNA-research would work? Why not just turn himself in?

Re:Sounds improbable

[Romwell]

Well, turning yourself in is admitting guilt and is psychologically hard. This way, he is not directly admitting guilt (he does the same thing 90% of people in the neighborhood are doing), and there's a chance they won't get him, so it probably is much easier to (effectively) turn oneself in this this way.

Re:Sounds improbable

[Hardhead_7]

I wondered about that too. Of course, if a few family members had already donated, and you knew it was only a matter of time before they caught you, it might be worth turning in your own DNA so you can later sow doubt with a "If I were really guilty, why would I have turned in my DNA?" defense.

Or maybe not. Who knows at this point?

Re:Sounds improbable

[RabbitWho]

If 96% of people had done it the social pressure might have been insurmountable. He might have figured if he was the only person in the village who didn't give DNA the police would investigate him and find him anyway, so he might as well give the DNA, hope that there would be a mistake, or hope that he could claim "If it was me, then why did I give them my DNA?"

Re:Sounds improbable

[IamTheRealMike]

The guy had a wife and child. If your wife starts saying "Hey you should do this" it's probably hard to say no to her, even if you know it'll result in doom. After all, if you aren't the type who normally cares about or talks about civil liberties it's probably hard to come up with a negative response that doesn't sound fishy as hell.

Re:Sounds improbable

[nschubach]

The guy had a wife and child. If your wife starts saying "Hey you should do this" it's probably hard to say no to her, even if you know it'll result in doom

If he had a wife like that, he probably did it because it would result in him being arrested.

Re:Sounds improbable

[BLKMGK]

The DNA matched DNA found on a cigarette lighter found in her schoolbag - not DNA from the rape itself apparently. It's possible in my mind that the guy is innocent of rape\murder and guilty of selling a schoolgirl a lighter or her guilty of stealing it. More details need to come out, this isn't "solved" in my mind unless they have DNA evidence from the rape itself that matches.

Re:Sounds improbable

[Baloroth]

If 96% of people had done it the social pressure might have been insurmountable. He might have figured if he was the only person in the village who didn't give DNA the police would investigate him and find him anyway, so he might as well give the DNA, hope that there would be a mistake, or hope that he could claim "If it was me, then why did I give them my DNA?"

That's why the US has the fifth amendment (and why a right against self-incrimination is a good idea in general). Not turning in DNA is not probable cause for an investigation, and if that is why they started investigating him, the case would have a high chance of being thrown out (of course, the family DNA might be enough to establish an investigation). I'm not sure what the law is on this in the Netherlands.

Re:Sounds improbable

[Anonymous Coward]

The DNA matched DNA found on a cigarette lighter found in her schoolbag - not DNA from the rape itself apparently.

The DNA on the lighter matched DNA from the rape itself. The importance of the lighter is that it was sold during the time of the rape in that narrow area - placing the rapist as a resident of that area at the time, and giving high probability that a scan of all the residents would strongly indicate who the attacker was. If the lighter wasn't found, this search couldn't be justified as the rapist could come from anywhere.

Re:Sounds improbable

[bp m_i_k_e]

It was more than a lighter exchange. Matching DNA was found on both the lighter and on the girl's body. That led to the DNA-dragnet. Apparently, the suspect's DNA matched the samples from her body and the lighter.

Re:Sounds improbable

[gr8_phk]

The DNA matched DNA found on a cigarette lighter found in her schoolbag - not DNA from the rape itself apparently .... More details need to come out, this isn't "solved" in my mind unless they have DNA evidence from the rape itself that matches.

Especially when they're admittedly going on a fishing expedition through the entire town. There is no doubt that there would be other peoples DNA on her personal belongings. Probably several peoples DNA from various places. This is exactly the kind of thing people are afraid of when they don't want their DNA in a database.

Re:Sounds improbable

[MozeeToby]

Even if it were DNA from the rape, I would have my doubts about their claimed "100%" number. Let's say it's really "only" 99.99%; they have 8000 samples, what are the odds that someone will match? Then you through in the fact that the 99.99% probably includes a truly random sample, which a small town is most assuredly not, and the odds of finding a false positive increase even more.

Re:Sounds improbable

[Anonymous Coward]

According to TFA, the lighter had DNA that matched trace collected from the girl's body. The lighter is significant because it was being sold in the area at the time of the crime, meaning that the murderer was likely local and not from abroad. This was what motivated the mass DNA testing - it was no longer a shot in the dark.

Re:Sounds improbable

[Crayon Kid]

That's why the US has the fifth amendment (and why a right against self-incrimination is a good idea in general).

Please elaborate on how this is a good thing, because I'm really confused about it. To me it sounds like, the police finally found a way to identify a murderer, but then this 5th amendment thingy comes in and it gets thrown out on a technicality. What's good about that?

I've read the Wikipedia entry about the self-incrimination aspect of it, to prevent confessions obtained under torture for example. But that's a far cry from what we have in this case.

Re:Sounds improbable

[wonkey_monkey]

Not turning in DNA is not probable cause for an investigation

Is "being the only remaining suspect living in the area" cause enough? Also, there's plenty of investigating that can be done without probable cause or a search warrant.

Re:Sounds improbable

[tibit]

Those "DNA matches" are not. AFAIK, what's matched a very tiny amount of information from the DNA. I figure there may be a reasonable probability that when you've got so many volunteers, there will be a "100%" match. I don't know what kind of "matching" they are using, of course, so feel free to correct me if I'm totally off-base.

Re:Sounds improbable

[Anubis IV]

No, that's patently incorrect. The article (which I read, shame on me) makes it clear that the DNA on the cigarette lighter matches DNA present on the body of the victim:

The decision to launch the dna appeal came after De Vries in May broadcast information about a Playboy cigarette lighter found in Vaatstra's bag which contains dna traces that match the traces found on the schoolgirl's body.

More or less, they found DNA on her body, but had no immediate reason to suspect it was from someone nearby. When they found the same DNA on the cigarette lighter and were able to determine that the cigarette lighter was on sale in that area around the date that the rape/murder occurred, they thought they had reason to suspect a local individual was involved. That's what led to the DNA dragnet.

I do agree that police need to be careful with DNA evidence and not use it as proof of guilt where it implies no such thing, but that does not seem to be the case here.

Re:Sounds improbable

[rtfa-troll]

What if it's a false positive?

Given that the chance of a false positive is normally between 1 in 100 and 1 in 1000 in DNA tests (this is based on cases where people have actually tested labs by sending them known matching and non matching samples - not the statistics of DNA) and they have carried out 8000 tests, that's pretty likely. Most likely they had multiple false positives, but he's the one which repeated when they retested. If he was actually guilty he probably wouldn't hand his sample in.

The most likely explanation, given that he's a farmer, is that his DNA was present on some food the lab technician put next to the original sample. Now there's no way he can prove his innocence (were were you on the 1st of May 1999? can you prove that?). He's fucked. Serves him right for trusting the police.

Let's see if the Dutch police actually investigate or if they just assume his guilt. From what I've seen whilst probably honest they're pretty narrow minded.

Re:Sounds improbable

[JudgeFurious]

Aren't they actually investigating the entire village and so if 96% of the men living there have eliminated themselves as suspects it would seem that then focusing on the remaining men who could still possibly have done it would be entirely correct. They'd be looking closer at him because he as one of only a handful of people left who could possibly be guilty.

Re:Sounds improbable

[martijn hoekstra]

"As it turned out, the man now in custody turned in his own DNA, resulting in a 100% match."

If he was really the guy who did it: Was he wondering whether the DNA-research would work? Why not just turn himself in?

It was a cold case. Maybe he forgot he was involved in a murder in the first place. "Oh, that murder case! I forgot all about that one... ...wait, give my DNA back, I don't want to volunteer!"

Re:Sounds improbable

[C0L0PH0N]

As pointed out in other posts, your statement, "not DNA from the rape itself", is completely incorrect. As the article says, "The decision to launch the DNA appeal came after De Vries in May broadcast information about a Playboy cigarette lighter found in Vaatstra's bag which contains DNA traces that match the traces found on the schoolgirl's body. " The DNA WAS found on the girl's raped body. Because it was ALSO found on a cigarette lighter sold locally, that is why they suspected a local person. So his DNA matches exactly that on the raped girl's body! At least, their approach was logical. Just to be clear.

Re:Sounds improbable

[jythie]

Even with the 5th amendment the US has had problems with dragnets in the past, the police needing a lead and rounding up 'the usual suspects' which in many cases became little more then harassment of weak populations. There is also the historical problem of defending yourself once the police have their eye on you.... there have been countless issues with bad (or just incomplete) science resulting in 'this person did it!' and the person having to prove otherwise on their own dollar.. which when you have these kind of broad searches you will generally find at least _someone_ who seems to be guilty... and then there is incredible political pressure on the police to have not 'screwed up' so they get invested in making sure the person they fingered.

Looking at some comments below, it appears that the DNA did not come from the crime itself but from a lighter found in the victim's schoolbag.. so now we have a dragnet to find someone who once touched a lighter found with a victim, and now the person's life is going to be turned upside down because of it. They may indeed be guilty, but such a broad search method is bound to find SOMEONE who can be presented to the public as the attacker. In the US at least this would probably destroy the person both financially and socially even if they are vindicated. The police on the other hand have lots to gain for finding someone to point to... thus they have a powerful incentive to use such tools but no real consequence for getting the wrong person. In the US at least there is some check to stop such dragnets.

Re:Sounds improbable

[wvmarle]

The "didn't turn in DNA" part is not necessary part of the evidence.

It narrows down the list of suspects, if only one doesn't give DNA the investigation can focus on that individual. If that person is indeed the culprit, there is a very good chance that other evidence is found, directly incriminating the person, and with enough evidence search warrants may be received for more detailed searches. If he is not the culprit, there will be no such evidence.

Re:Sounds improbable

[mark-t]

The *ONLY* way you can get a 100% match with a false positive with a legitimate DNA test is if the subject has an identical sibling.

Re:Sounds improbable

[westlake]

That's why the US has the fifth amendment (and why a right against self-incrimination is a good idea in general).

In US law, the privilege against self-incrimination is ultimately rooted as a barrier against the use of isolation, intimidation and torture to extract confessions.

There is much you cannot be forced to say.

But very few barriers to the physical evidence you may be compelled to surrender.

I am not convinced that, under US law the barrier to launching an investigation against a particular person is anywhere near as high as that needed to support a search and seizure.

Re:Sounds improbable

[SkunkPussy]

contamination, procedural error etc.

Re:Sounds improbable

[Cederic]

No, it would mean that DNA is not a positive test for guilt.

It can be a positive test for innocence: If my DNA markers differ from that of sperm found in a rape victim then I didn't rape her.

A positive DNA test seems reasonable grounds for further investigation, but is not in itself sufficient evidence of guilt. Even if they tested the full length of DNA (and they don't even get close) there have been many examples of contamination that invalidates results.

Re:Sounds improbable

[rtfa-troll]

A regular DNA test has about 1/10000 success rate, but I would think that one can run a more thorough test (for a cost) that is much more precise than that. DNA doesn't have that collision rate.

That's the theoretical rate based on calculating the genetics of the population; it assumes that you run the scan perfectly. In fact labs make mistakes and cross contamination happens. This is something where the basic principle of science; actually do the experiment and see; must override the theory.

When people actually the lab error rate for genetic tests they get numbers like 1.7 in 1000 measured false positive rate. If you know a set of results where independent blind testing of the Dutch police DNA system has returned better results, please point to your peer reviewed study which shows so. I believe that most police labs aren't even subject to blind testing, so an even higher error rate should be expected.

Re:Sounds improbable

[NotSanguine]

That's why the US has the fifth amendment (and why a right against self-incrimination is a good idea in general).

Please elaborate on how this is a good thing, because I'm really confused about it. To me it sounds like, the police finally found a way to identify a murderer, but then this 5th amendment thingy comes in and it gets thrown out on a technicality. What's good about that?

I've read the Wikipedia entry about the self-incrimination aspect of it, to prevent confessions obtained under torture for example. But that's a far cry from what we have in this case.

The relevant Fifth Amendment protection reads:

...nor shall be compelled in any criminal case to be a witness against himself,

US courts have ruled that a criminal suspect/defendant may not refuse DNA testing based on their Fifth Amendment rights. However, the Fourth Amendment requires a warrant issued by a judge before a "search" can be performed.

US courts have ruled that (except for convicted felons and other narrow exceptions) police must obtain a warrant before coercing someone to give up a DNA sample.

However, based on the 1985 California v. Greenwood case, if you spit on the sidewalk, throw away a cigarette butt or lick a stamp, then legally you have "abandoned" the DNA and police can collect it without a warrant. California v. Greenwood focused on household garbage placed in bins outside your curtilage, but that reasoning was expanded to include "abandoned" DNA as well.

N.B., IANAL

Re:Sounds improbable

[SourceFrog]

What if it's a false positive?

Also, for those who think this is extremely unlikely and automatically believe DNA evidence is some sort of slam-dunk:

Teenager wrongly accused of rape (and imprisoned) because of DNA contamination (fortunately, it was picked up in this case)

DNA evidence contamination leads to review of 7,000 cases The police in Victoria are reviewing 7,000 cases involving DNA evidence after they had to withdraw murder charges in a high profile cold case. Police now say they deeply regret having charged a man with the murders of Margaret Tapp and her daughter Seana, at their home in 1984. They charged Russell Gesah two weeks ago, but since then problems have emerged with the DNA evidence.

DNA rape sample procedures 'not adequate' Adam Scott, from Devon, was held for a couple of months after being accused of raping a woman in Manchester. The charges were dropped when it emerged a DNA sample had been contaminated at LGC Forensics.

Police Fear 'Serial Killer' Was Just DNA Contamination A notorious German serial killer known as "the Phantom of Heilbronn" might not exist. Police believe DNA evidence which pointed to a 15-year trail of crimes across Germany was a case of contaminated cotton swabs.

Aerosolized Vaccine as an Unexpected Source of False-Positive Bordetella pertussis PCR Results etc.

Privacy issue: DNA dragnets

[concealment]

I don't like the idea of DNA dragnets.

Just because I'm a male within 5km of a rape does not mean I should be required to give up my DNA.

First, who owns it? Does it get destroyed? Do I trust government to do that competently? No: it will be sold to the highest bidder.

Second, am I coerced into doing this? Will they shame me publicly for not giving up my DNA?

Finally, who else knows about it? Is my health insurance going up because they've found I'm susceptible to lung cancer or AIDS? What if there's a way to tell if I'm gay or prone to alcoholism (hic)?

There's got to be a better way to solve these rapes than asking all of us to give up private information at the threat of arrest.

Re:Privacy issue: DNA dragnets

[SJHillman]

Assuming you're referring to this article in particular, let me define the most important word in the summary.
volunteer/välnti()r/
Noun: A person who freely offers to take part in an enterprise or undertake a task.
Verb: Freely offer to do something

If you're referring to some possible future event that may or may not happen and is vaguely related to this, then please disregard.

Re:Privacy issue: DNA dragnets

[crazyjj]

But when does it stop being voluntary? It's voluntary now. But a few cases like this will make it very tempting for lawmakers to move to the next level (making it mandatory for particular areas in particular investigations). And from there, to making it mandatory for the entire citizenry. And from there, to including scans for potential diseases in the database (for the public health, of course). And from there, to insurance companies wanting access to that info....and so on. Pretty soon you could be in a Gattaca type situation.

Not saying this is going to happen, or that one step necessarily has to follow from the previous. But you have to understand why this particular slippery slope makes a LOT of people VERY nervous.

Re:Privacy issue: DNA dragnets

[Sydin]

If you'd taken the additional ten seconds required to actually read more than just the headline, you would have stumbled upon the fact that nothing was "required" of anybody. It was strictly on a volunteer basis. In some countries, and I know this is a shock to those living in the USA, governments still consider people innocent until proven guilty. These people were being asked to provide assistance to their police force in order to catch a rapist, and the vast majority chose to do just that. You'll notice that there's nothing stating the 10% who refused are behind bars right now, and that's because deciding NOT to turn in your DNA due to privacy or other such concerns does not instantly make you guilty of suspicion. The anti-government, anti-police stance on this website rivals that of a Ron Paul fanclub forum. Protip: Not all cops are corrupt, and not all governments want to slam a boot down onto your face forever.

Re:Privacy issue: DNA dragnets

[L4t3r4lu5]

Here's another word for you:

Definition of COERCE 1: to restrain or dominate by force
2: to compel to an act or choice
3: to achieve by force or threat

"Give us your DNA so we can catch a rapist" fits definition 2 pretty well, don't you think?

Re:Privacy issue: DNA dragnets

[cryptolemur]

It's not that slippery a slope. At least, where I live, neither DNA collected for any research purpose or fingerprints for passports can not be used in criminal investigation, no matter what. That's the law.
Now, it can be argued that the law can e changed anytime "the government" feels like it, but then again, by the same logic the law could also be changed to require everybody to wear AV-recording devices 24/7 at the convenience of "the government"...

Re:Privacy issue: DNA dragnets

[medv4380]

There really ins't a better way. DNA really is our only answer to the issue of Justice in relation to sever crimes like Rape and Murder. People are falsely accused of Rape and Murder all the time, and occasionally we find out about it. Hopefully before we put them to death or destroy their lives. The end goal it to make it so that you cant do those things without getting caught. It's got to the point were Rapists have been doing things to reduce the chance of their DNA being present. Which also reduced the odds that a Rape would result in a child since I don't know of any way of a child being conceived without leaving some DNA behind. If you believe that Rapists are a result of bad genetics taking advantage of sexual reproduction to gain a marginal reproductive advantage then they are weeding themselves out. Ether they use protection to avoid detection, or they don't and they get caught. That along with free morning after pills for rape victims and you'll see a drastic decline in the people willing to Rape others. Murder is a bit different but if we get to the point where premeditated murder is unheard of, and are left only with crimes of passion then I'll be satisfied with the results. As bad as Rape and Murder is punishing Innocent people is much worse. DNA alone shouldn't convict, but it is a very good start. You're argument of "There's got to be a better way to solve these rapes than asking all of us to give up private information at the threat of arrest." is also a Red Herring. No one in the article was threatened with prison time for not volunteering their DNA. If you're stupid enough to commit a crime, and then submit your DNA voluntarily to be checked against said crime You're a Moron and deserve the Darwin Award. What they were hoping for was a Parent, Child or Grandchild to donate their DNA to help narrow down the list of possible suspects. Their was always the possibility that the suspect was already dead, or not stupid enough to submit his own DNA.

Re:Privacy issue: DNA dragnets

[menno_h]

Actually, the local chief of police said they wouldn't (on a show on national television). The chance of one of your relatives submitting DNA is so large that they'll be able to arrest you if you are guilty, even if you didn't give them anything.

Re:Privacy issue: DNA dragnets

[rhsanborn]

Not here. I was fingerprinted to run it against the FBI database to make sure I didn't have a previous record. I couldn't get employment without that background check. The FBI put my fingerprints in their system, and now, will have them as a reference. Of course, I shouldn't have anything to worry about, since I don't plan on doing anything wrong. Fortunately, no one was ever put in prison on circumstantial evidence ...

Of course, the FBI isn't interested in making a DNA database of people not convicted of a crime.

Re:Privacy issue: DNA dragnets

[coldfarnorth]

Yes, yes, you can copy and paste from a dictionary too.

This is no more compulsion than saying "I'll pay you $5 to mow my lawn" compels you to do break out the lawn mower.

Anyone could have said "No thanks" and that would have been the end of it, so no, definition 2 does not fit.

Re:Privacy issue: DNA dragnets

[coldfarnorth]

I'm sorry, "all the cool kids are doing it", or "I'm really disappointed with you for not doing this" is not the same as compulsion. As others have already mentioned, this was occurring in a fairly small town, so the odds of one of your family members contributing a sample and incrimination (or exonerating) you is fairly high, regardless of your decision.

Just to clarify one thing:

If you have to make a decision where choice 1 results for more (subjective) unpleasantness for you than choice 2, that doesn't mean that you are compelled to chose choice 2.

The world's full of trade-offs, and if keeping your DNA in your own pants is worth a little Q&A with the police, then be prepared to do that. If they come after you with a $5 wrench, I agree that it's moved in to coercion, but putting up with a little pointed questioning . . . put on your big girl panties and deal with it.

Sample Size

[Jamu]

I wonder how big the sample size would need to be to get two 100% matches.

Re:Sample Size

[coolsnowmen]

(in addition to the identical twin comments), the change of collision drastically changes depending of the type of DNA comparison test being performed. Usually this is a function of how many allele's they are testing for.

Don't jump to conclusions

[sideslash]

We have to be careful treating technology like this as an infallible oracle.

- Technicians could have made a mistake.
- Our understanding of the science of genetic matching could be flawed in ways that we haven't come to realize yet.
- The guy could have had consensual relations with the girl (creepy though that is) and somebody different murdered her.

It's strange that he volunteered a DNA sample. Hopefully that's just because most criminals are dumb, and not because he's being wrongly accused.

Solved?

[The_Noid]

Everybody in the Dutch talks as if the man is convicted already. He's not. The case is not solved until a judge has had the last word, and given the inaccuracies in DNA matching I'm very interested in what a judge has to say about this.

Re:Solved?

[jiriw]

Everybody in the Dutch talks as if the man is convicted already.

Ok .. this is so untrue...

This is the news article from the major Dutch online newspaper. Put it through Google translate if you don't trust my translations:

nu.nl

AMSTERDAM - A suspect has been apprehended in the 'Marianne Vaatstra' case. The Procesution Councel (PC) confirmed it this monday morning.

...

The Justice dept. will not reveal any details for now. The PC and Frysian police force will hold a press conference 18:00 CET in Drachten.

...

The Dutch Forensics Institution (NFI) is currently performing a minute double-check of the identity of the suspect.
"For both PC and police force it's of major concern we only submit an official statement to the press when it's certain the identity of the suspect is confirmed without question by the NFI."

...

Moreover [the spokeswoman of the PC] emphasizes DNA will 'never be enough', "there always will need to be more evidence".

DNA database

[Anonymous Coward]

In Sweden we have the PKU-registry. Anyone born after 1975 has a DNA sample taken from them at birth, however it can only be used for your own treatment, identification of remains or research. So far they have kept their part of the promise of not letting it be used for criminal prosecution. Even tho as some would like it to be included in tools available for the police.

Re:Idiot

[Jesrad]

Assuming the person arrested is not guilty, it could just be a false positive match. DNA tests are not 100% precise, in fact I read they are 99.7% precise only, resulting in approximately 1-in-300 errors, so in any wide-ranging tests with thousands of different DNAs all coming from the same area (meaning most of them had a lot of common ancestors across them) it was almost bound to happen. Imagine the uproar if TWO 100% matches had been found (and I do not mean homozygote twins) !

Note that roughly 1 in 10-15 person has more than one set of DNA, through chimerism - rare - or plain mosaicism - which is much more common than usually thought: that's part of how you can get "surprising" results of >10% paternity tests turning out negative in countries where those tests are sold over the counter. There are documented cases of botched criminal cases due to this, the most famous being Linda "I'm my own twin" Fairchild's.

And if he IS guilty then it may be one way to work up doubt into a future jury, using precisely those arguments. So, it's not necessarily idiotic.

Re:Solved? Not quite.

[MeepMeep]

I know this is breaking the rules, but I've read TFA. The DNA sample was found on a lighter in the girl's bag next to her body.

Not just on the lighter

From TFA:
" ...cigarette lighter found in Vaatstra's bag which contains dna traces that match the traces found on the schoolgirl's body. "

Mod parent up

[crazyjj]

That's a VERY important point in this case. People hear "DNA" these days and automatically think "irrefutable evidence." But in this case, it's just further evidence--NOT ironclad proof of guilt.

Prosecutor's Fallacy

[McGregorMortis]

I haven't RTFA, but from the summary, this sounds like a textbook example of the http://en.wikipedia.org/wiki/Prosecutor's_fallacy, which is a special case of the http://en.wikipedia.org/wiki/Base_rate_fallacy

If you have a suspect in hand, then DNA evidence can be pretty compelling. But when you comb through the population trying to find a suspect using DNA evidence, then you're walking straight into a miscarriage of justice.

Re:Prosecutor's Fallacy

[photon317]

No mod points today, but it sounds like you're right. Deep link to specific example that sounds exactly like this case: http://en.wikipedia.org/wiki/Prosecutor's_fallacy#Multiple_testing

Re:Prosecutor's Fallacy

[coldfarnorth]

There are a few more details that make the Prosecutor's Fallacy less applicable to this situation. First, they are looking at a relatively small population, so the odds of two unrelated matches is lower than if you were scanning a database of millions of profiles. Second, they have a pretty complete picture of the population that they are searching, so duplicate matches can be investigated. Third, this is all just evidence at this point - the trial is yet to be carried out. Assuming that a miscarriage of justice is going to occur because large quantities of DNA evidence was used seems a bit harsh for this early in the game.

Exactly

[Anonymous Coward]

If government is involved, there is no "volunteering". The threat of physical force is ALWAYS present with government, no matter how far under the carpet they sweep it, or how much smokescreen they blow in front of it.

Re:Exactly

[Anonymous Coward]

A few years back, the TSA had just started requiring people to put their shoes through the X-ray scanner, but it wasn't completely mandatory yet. At one airport, we were informed that we didn't have to take off our shoes, but if we didn't, we could be subject to additional security. Needless to say, everyone "voluntarily" took their shoes off. If there's a punishment for not complying, it isn't voluntary.

Re:Exactly

[guises]

Wasn't this the reasoning behind the "enhanced patdown" procedure? To get more people to go through the nudie scanners? I recall the head of the TSA said this explicitly.

Re:Exactly

[Incadenza]

Here in the Netherlands there is. It is unlawful to take anything from your body without your consent. Material taken without your consent cannot be used as a proof. A couple of years ago they tricked somebody into a friendly chat at the police station, including a cup of coffee on the house. Afterwards the cup was sent to the DNA lab for all the DNA traces he had left on them! End result: the guy was set free, because the proof was unlawful.

Re:Idiot

[Cederic]

At least one study agrees with you:
http://link.springer.com/article/10.1007%2FBF01542085?LI=true#page-1

Re:oblig tsa reference

[s0nicfreak]

IMO it's only molestation if the person doing the act enjoys it sexually. Otherwise you could say parents "molest" their babies every time they change a diaper.