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Dutch Cold Case Murder Solved After 8000 People Gave Their DNA

Posted by samzenpus on from the check-me dept.

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%."

21 of 513 comments (clear)

  1. Interesting by MyLongNickName · · Score: 5, Insightful

    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.

    --
    See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
    1. Re:Interesting by Anonymous Coward · · Score: 5, Insightful

      "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."

    2. Re:Interesting by readin · · Score: 5, Interesting

      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.

      --
      I often don't like the choices people make, but I like the fact that people make choices. That's why I'm a conservative.
    3. Re:Interesting by interkin3tic · · Score: 5, Insightful

      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.

    4. Re:Interesting by Anonymous Coward · · Score: 5, Informative

      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.

    5. Re:Interesting by Pete+(big-pete) · · Score: 5, Informative

      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.

      --
      Monochrome - Probably the UK's largest internet BBS
    6. Re:Interesting by Capt.DrumkenBum · · Score: 5, Insightful

      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.

      --
      If I were God, wouldn't I protect my churches from acts of me?
    7. Re:Interesting by mariox19 · · Score: 5, Insightful

      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?

      --

      quiquid id est, timeo puellas et oscula dantes.

  2. Sounds improbable by dinfinity · · Score: 5, Interesting

    "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?

    1. Re:Sounds improbable by RabbitWho · · Score: 5, Interesting

      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?"

      --
      it's under construction
    2. Re:Sounds improbable by nschubach · · Score: 5, Funny

      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.

      --
      Every time I start to have faith in humanity, I ruin it by driving to work between 7 and 8 am.
    3. Re:Sounds improbable by BLKMGK · · Score: 5, Insightful

      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.

      --
      Build it, Drive it, Improve it! Hybridz.org
    4. Re:Sounds improbable by Anonymous Coward · · Score: 5, Informative

      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.

    5. Re:Sounds improbable by bp+m_i_k_e · · Score: 5, Informative

      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.

    6. Re:Sounds improbable by Anubis+IV · · Score: 5, Informative

      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.

    7. Re:Sounds improbable by rtfa-troll · · Score: 5, Insightful

      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.

      --
      =~ s,(.*),<sarcasm>$1</sarcasm>,g if any_point_you_wish();
    8. Re:Sounds improbable by rtfa-troll · · Score: 5, Informative

      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.

      --
      =~ s,(.*),<sarcasm>$1</sarcasm>,g if any_point_you_wish();
  3. Privacy issue: DNA dragnets by concealment · · Score: 5, Insightful

    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.

  4. Mod parent up by crazyjj · · Score: 5, Insightful

    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.

    --
    What political party do you join when you don't like Bible-thumpers *or* hippies?
  5. Prosecutor's Fallacy by McGregorMortis · · Score: 5, Insightful

    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.

  6. Re:Exactly by Anonymous Coward · · Score: 5, Insightful

    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.