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Crime Biotech Science

Twins' DNA Foils Police 209

Hugh Pickens writes "The Telegraph reports that James and John Parr were both arrested after watches worth £10,000 were stolen from a shopping center. Police found blood on a piece of glass at the scene of the crime and traced it back to the 25-year-old identical twins through DNA tests. But James and John both denied the theft and, because they have identical DNA, it has been impossible to prove beyond a reasonable doubt which twin is responsible. 'The police told us that they knew it was one of us, but we both denied it,' says James. 'I definitely know I didn't do anything wrong. I was watching my daughter that night.' Now the Crown Prosecution Service (CPS) has concluded that it cannot prove beyond reasonable doubt who was responsible. 'Unless further evidence becomes available, we are unable to authorize any charge at this time,' says CPS spokesman Rob Pett. 'This is certainly not something that we regularly encounter.' Identical twins have hindered police investigations a number of times since the advent of DNA testing. In Malaysia last year, a man suspected of drug-smuggling and sentenced to death was released when the court could not prove whether it was he or his twin brother who committed the crime."
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Twins' DNA Foils Police

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  • Um, this is easy (Score:4, Insightful)

    by HighOrbit ( 631451 ) on Saturday April 03, 2010 @01:38PM (#31716986)
    Which one has the cut that left the blood behind?
    • Re:Um, this is easy (Score:4, Interesting)

      by Threni ( 635302 ) on Saturday April 03, 2010 @01:51PM (#31717086)

      And which one cut himself opening catfood. You don't go to prison for cutting yourself feeding your cat, right?

    • by TheRaven64 ( 641858 ) on Saturday April 03, 2010 @01:59PM (#31717166) Journal
      Who says it was either of them? DNA fingerprints are not unique. There are likely to be 50 other people in the UK with the same DNA fingerprint as the twins and it's entirely possible that one of them was the robber. The depressing thing is that the police seem to think that this is enough evidence to convict even if there is no other evidence, unless they happen to randomly find two people with the same DNA fingerprint.
    • by Kozz ( 7764 ) on Saturday April 03, 2010 @02:12PM (#31717334)

      If the twins have not been living near-identical lives (sharing cars, apartments, etc), they probably have distinct bacterial colonies, and bacterial forensics (an emerging science) could be the key.

      http://www.sciencefriday.com/program/archives/201003193 [sciencefriday.com]

      This method cannot conclusively place an individual at the scene of the crime, but if combined with DNA evidence, I think you'd have a pretty air-tight case.

    • Just because a cut's shape is consistent with the broken glass don't make it so. Plus there's the possibility that the blood was planted, which gets better the more police can't tie either brother to the crime by conventional investigation. Who knows, maybe they sold a blood sample to the real thief to throw off the cops knowing it couldn't be pinned on either of them.
  • Old days? (Score:5, Insightful)

    by Anonymous Coward on Saturday April 03, 2010 @01:39PM (#31716990)
    So DNA is the only way to prove guilt and find the truth? I remember in the old days, before DNA, they were still able to catch criminals. Maybe they should find some retired police officers to see how it's really done.
    • Re: (Score:3, Insightful)

      by Draek ( 916851 )

      I know dissing new technology and looking to the past with rose-tinted glasses is all the rage these days, but don't you think that if they had any other leads, they would've pursued them as well?

      Besides, not only did the old methods catch only some criminals (so do the newer ones, but for higher values of 'some'), many of those they did catch ended up decades later to not have been criminals after all.

    • Re: (Score:3, Insightful)

      by Xeno man ( 1614779 )
      Without DNA they wouldn't even have a suspect. In the old days this would have just been another unsolved crime.
  • Just goes to show (Score:5, Insightful)

    by azaris ( 699901 ) on Saturday April 03, 2010 @01:40PM (#31716998) Journal
    DNA by itself should never be used as the sole evidence to convict someone. It can be a useful indicator for finding suspects, but there always needs to be more direct evidence to provide a conviction. It is not just that people who don't have twins can be convicted solely based on DNA evidence, while people who do have twins cannot because of the possibility of convicting an innocent person. And that is not even going into DNA collisions or tainted samples.
  • I've never though that blood at the scene means you were at the scene, or that you did a crime that was committed at that location.

    • Re: (Score:2, Insightful)

      by Threni ( 635302 )

      You blood at the scene means you get to explain to the police how it got there. If your blood was in my kitchen, next to my wifes body, and there was evidence she fought her attacker, you don't think the police, having matched the mystery blood back to you, wouldn't want a quick word with you?

  • Hmmm. This has possibilities. I always wondered how I could make a profit from having identical twin kids.

    Seriously, they might be able to do a serological comparison but I doubt that the technology is there yet.

  • Wait until I get some clones, then nothing will stop me from world domination.
    • Given the amazingly poor security of many law enforcement and medical databases, wouldn't it be easier to simply swap the data with some innocent sucker?

  • So the solution to genetic privacy is for us all to clone ourselves!

    Good thing we"ll have all those genegeneered crops to feed them clones.

  • by algormortis ( 1422619 ) on Saturday April 03, 2010 @01:50PM (#31717084)

    ...a man suspected of drug-smuggling and sentenced to death...

    I'm surprised nobody has said anything about this. Sentenced to death for smuggling drugs? That's more of a problem than twin's getting away with theft and... well... drug smuggling.

    • Re: (Score:3, Informative)

      If I recall correctly, death sentences for drug smuggling are pretty common in the region.

    • China, Taiwan, Malaysia, the Philippines and probably a bunch of other countries in the region carry the death penalty for drug smuggling, and have for decades. This is nothing new.
  • DNA to find out if you've been at a crime-scene gets all the attention but what about family? Using genetics it is possible to narrow down whether or not someones DNA who is on file is a relative of someone's who is not. So, all of a sudden the police may have probable cause to investigate families instead of individuals. Privacy is an issue here, can I be compelled to add my DNA to a database because I happen to be in the same branch of genes as someone who committed a crime? And what is crime: with th
  • Well, good. (Score:3, Insightful)

    by bmo ( 77928 ) on Saturday April 03, 2010 @01:57PM (#31717156)

    This is the way it's supposed to work. DNA is not a magic bullet (heh) for solving crimes.

    So the Crown will have to use good old fashioned police work to prove the case, like finding the watch in either twin's possession and/or fingerprints on the broken glass. Even genetic twins have different fingerprints. If the Crown (or any other prosecutorial system based upon English Common Law) cannot do this, then they go free, as per the design of the system.

    It's better to let a hundred guilty go free than to jail (or execute!) one innocent person.


  • Actually, he's not evil at all. He's just into bigger engines than I am. http://www.selectric.org/ [selectric.org] vs http://www.cathodecorner.com/ [cathodecorner.com]
  • They BOTH did it.

    • by moteyalpha ( 1228680 ) on Saturday April 03, 2010 @02:18PM (#31717388) Homepage Journal
      No, my theory is they are telling the truth. What they lied about ( by omission ) is that they are triplets and if they had found the third he would have admitted to the crime.
  • by goodmanj ( 234846 ) on Saturday April 03, 2010 @02:11PM (#31717332)

    ... not as defendant, but as a juror.

    I served on a jury last summer for a case of armed home invasion. The victim, if you can call him that, was a multiply-convicted white crack user. The victim claimed the defendant forced his way into the defendant's house with a gun, as part of a dispute over the defendant's missing cell phone following a drug deal.

    The defense attorney's goal was to convince us that there was no way to determine beyond a reasonable doubt whether the defendant committed the crime, or his brother. The police did a horribly sloppy job of gathering evidence, the DNA was so contaminated that while it matched the victim, it also had good odds of matching the defendant's brother or about 1 in 5 random people off the street. The victim lied on the stand several times and showed no reliability as an eyewitness, and all the other evidence (phone calls, evidence collected at defendant's house) pointed to *some* member of the defendant's family, but no way to know who.

    So we found him not guilty. Kind of a shame since the defendant probably *was* a drug dealer, but no way to prove it wasn't his brother. And the kicker: if they bring the brother to trial, he can use the same defense.

  • When two people are on an elevator and one farts, they both know who did it.

  • by ChrisCampbell47 ( 181542 ) on Saturday April 03, 2010 @02:35PM (#31717552)

    DNA has been getting relied on heavily lately to solve otherwise cold cases. States have started running crime scene evidence through DNA databases wholesale, and then running with whatever match they get, even if it's just a partial.

    Think about it: if there's a one in a million chance that the DNA will match, and you have a 20 million person database, then you're going to get 20 matches. Now just find the guy who's most convenient to prosecute. Boom, instant cold case conversion!

    DNA's Dirty Little Secret: a forensic tool renowned for exonerating the innocent may actually be putting them in prison
    http://www.washingtonmonthly.com/features/2010/1003.bobelian.html [washingtonmonthly.com]


    New Rule Allows Use of Partial DNA Matches
    http://www.nytimes.com/2010/01/25/nyregion/25dna.html [nytimes.com]

    DNA Evidence Can Be Fabricated, Scientists Show
    http://www.nytimes.com/2009/08/18/science/18dna.html [nytimes.com]

  • For folks that are familiar with Monty Python, the Piranha Brothers (fictional, http://en.wikipedia.org/wiki/Piranha_Brothers [wikipedia.org] were inspired by the Krays (real, http://en.wikipedia.org/wiki/Kray_brothers [wikipedia.org]).

    The Krays stayed out of prison for a long time by intimidating witnesses. DNA evidence cannot be intimidated, but given this case, one the brothers could commit a crime, without worrying about leaving DNA behind. Both would claim innocence. They could have called it the "Other Other Other Other Operat

  • When are the courts going to get it through their heads that it doesn't take identical twins to make DNA tests fallible and utterly unsuited as sole evidence?

  • ... is to make being an identical twin illegal. Bang. Problem solved. Both are guilty of something.
  • Surely, there are other tests using standard blood chemistry that could be performed? A standard annual blood test would test for a whole variety of things - glucose levels, hormone levels, antibody levels.

    Wouldn't the brothers have different glucos levels, immune responses or ratios of antibodies?

    • by topham ( 32406 )

      Glucos varies constantly, so unless one developed a condition like Diabetes it won't help. As for the rest, you'd still have to prove it's sufficient to identify a person. If it hasn't been used to do so in the past it is unlikely to pass muster in court.

      Never mind that most of the differences would have degraded in the sample to meaningless crap, DNA is pretty hardy stuff.

  • But to detect that, you'd have sequence much of their DNA. Perhaps partially sequencing using a SNP array chip might catch a mutation or two (23andMe uses these chips). Both techniques would be expensive. Conventional forensic DNA analysis looks at 30 markers. These would be the same for most identical twins.
    The 60 mutation number comes from a study reported a few weeks ago fully sequencing parents and an offspring.

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