Dutch Cold Case Murder Solved After 8000 People Gave Their DNA 513
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%."
Interesting (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.
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Lucky to get 1% before the ACLU (Or some other group) files suit to block
Re:Interesting (Score:5, Insightful)
Re:Interesting (Score:5, Insightful)
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 (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?
Re:Interesting (Score:4, Interesting)
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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.
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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.
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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 t
Re:Interesting (Score:5, Insightful)
Re:Interesting (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."
Exactly (Score:4, Insightful)
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 (Score:5, Insightful)
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Re:Exactly (Score:4, Informative)
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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 (Score:5, Insightful)
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 [www.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.
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Re:Interesting (Score:5, Informative)
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.
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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?
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. Whil
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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 princ
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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.
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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 (Score:5, Interesting)
Re:Interesting (Score:4, Informative)
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/ [lawreader.com]
http://www.deathpenaltyinfo.org/accuracy-dna-matches-definitively-identify-suspects-questioned [deathpenaltyinfo.org]
Re:Interesting (Score:5, Informative)
Re:Interesting (Score:5, Interesting)
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.
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You are wrong. They don't sequence and compare your entire genome.
Re:Interesting (Score:5, Interesting)
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.
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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 (Score:5, Informative)
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.
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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?
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Re:Interesting (Score:5, Interesting)
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.
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Sounds improbable (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?
Re:Sounds improbable (Score:5, Interesting)
Re:Sounds improbable (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.
Re:Sounds improbable (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 [bmj.com] 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.
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contamination, procedural error etc.
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Or maybe not. Who knows at this point?
Re:Sounds improbable (Score:5, Interesting)
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.
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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 (Score:5, Interesting)
Re:Sounds improbable (Score:5, Insightful)
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.
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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 exampl
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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 [wikipedia.org] protection reads:
US courts have ruled that a criminal suspect/defendant may not refuse DNA testing based on their Fifth Amendment rights. However, the Fourth Amendment [wikipedia.org] 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.
Ho
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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.
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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.
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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 (Score:5, Interesting)
Re:Sounds improbable (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.
Re:Sounds improbable (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.
Mod parent up (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.
Re:Sounds improbable (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.
Re:Sounds improbable (Score:5, Informative)
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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 a
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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 (Score:4, Informative)
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 (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.
Re:Sounds improbable (Score:4, Informative)
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"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!"
Privacy issue: DNA dragnets (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.
Re:Privacy issue: DNA dragnets (Score:5, Informative)
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 (Score:4, Insightful)
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 [wikipedia.org] 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.
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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 (Score:5, Insightful)
Of course, the FBI isn't interested in making a DNA database of people not convicted of a crime [nytimes.com].
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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?
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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.
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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 m
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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.
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Who said anything about being it being required?
Did you not notice the less 100% participation rate in the summary?
This was totally voluntary. If you do not like their answers to your questions you don't give it. Now stop karma whoring and read the fine article.
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Re:Privacy issue: DNA dragnets (Score:5, Interesting)
Sample Size (Score:4, Interesting)
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(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.
Really? (Score:2)
It seems rather unlikely to me that if you committed a crime you would volunteer into giving your DNA in this sort of style. Was it a full match or just based on a few key metrics, which seems the most common form of testing? It could be family of him, for instance.
Don't jump to conclusions (Score:3)
- 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.
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And since the sample was found on a lighter in her bag, "consensual relations" here might mean, "Hey, mister, got a light?" "Sure, keep it." He might be guilty of abetting under-age smoking, nothing more.
Case Solved ? (Score:2)
The DNA test was remarkably accurate (Score:2)
The makers guaranteed that the rate of false positives was only one in 8000. :-P
Solved? (Score:5, Insightful)
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.
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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 [www.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 (Score:4, Interesting)
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.
Prosecutor's Fallacy (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 [wikipedia.org], which is a special case of the http://en.wikipedia.org/wiki/Base_rate_fallacy [wikipedia.org]
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.
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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 [wikipedia.org]
Re:Prosecutor's Fallacy (Score:5, Insightful)
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.
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You can swab my tongue when you wrench it out of my cold, dead, mouth.
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I agree with you. But if the DNA match sperm on the girl's body, then it is pretty damning. You are right that an investigation should take place, but it is hard to explain outside of some type of consensual relationship and the guy not coming forward originally to help the investigation.
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You missed the part in the article where samples were found on her body as well.
Re: (Score:2)
Here is the relevant text
"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."
Re:Idiot (Score:4, Insightful)
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: (Score:3)
At least one study agrees with you:
http://link.springer.com/article/10.1007%2FBF01542085?LI=true#page-1 [springer.com]
Re:Solved? Not quite. (Score:5, Informative)
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. "
"
Re: (Score:2)
Ooops. Still, inaccurate information on /. - who'd've thought?