Slashdot Mirror


French Police Unsure Which Twin To Charge In Sexual Assaults

An anonymous reader writes "In a real life Prisoner's Dilemma taking place in the French city of Marseille, twin brothers have been arrested for a string of sexual assaults. While say they are sure that one of them committed the crimes (corroborated by a standard DNA test), police were told that it would cost upwards of €1m euros (£850,000, $1.3m USD) to distinguish between them using DNA evidence."

52 of 626 comments (clear)

  1. !(Prisoner's Dilemma) by Anonymous Coward · · Score: 5, Informative

    "Prisoner's Dilemma" does not just mean "a dilemma involving prisoners"

    1. Re:!(Prisoner's Dilemma) by Anonymous Coward · · Score: 3, Funny

      mind == blown!

    2. Re:!(Prisoner's Dilemma) by TheRealMindChild · · Score: 3, Informative

      This isn't reddit. There is no karma train

      --

      "When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
    3. Re:!(Prisoner's Dilemma) by Tubal-Cain · · Score: 4, Insightful

      It's the brothers that have the dilemma. Let's say both of them were committing these crimes:
      If both stay silent, maybe end up with time served 'cause they can't be sure it which of you it was.
      If one brother rats the other out (with convincing proof), he goes free while the other gets sentenced for all the crimes.
      If both rat the other out, each gets sentenced for his actual share of the crimes.

    4. Re:!(Prisoner's Dilemma) by RedHackTea · · Score: 3, Funny

      Mind equals blown not? Yoda language?

      --
      The G
    5. Re:!(Prisoner's Dilemma) by Anonymous Coward · · Score: 5, Insightful

      Yes, there is. There's just an upper bound to how much you can get here.

    6. Re:!(Prisoner's Dilemma) by angel'o'sphere · · Score: 5, Interesting

      That is nonsense:
      If both stay silent, maybe end up with time served 'cause they can't be sure it which of you it was.
      You can not convict someone on that base.

      Supposed I was innocent. Then according to the DNA evidence my twin did it. When he and I stay silent, they still don't know who it was. So the first paragraph of all "constitutional states": innocent until proven otherwise comes to play.

      --
      Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
    7. Re:!(Prisoner's Dilemma) by farble1670 · · Score: 4, Interesting

      it doesn't matter which twin committed the sexual assault, they are both guilty. one is guilty of conspiracy because he's lying for the other, and the other is guilty of sexual assault.

    8. Re:!(Prisoner's Dilemma) by roc97007 · · Score: 3, Insightful

      I assume both twins are guilty. With ovemr a dozen cases it looks like always one was commiting a crime and the other one tried to fabricate an alibi.

      Doesn't change the solution. If both twins are guilty, a detailed DNA analysis will still be necessary to pin the correct crime to the correct twin. You don't get to be convicted just because you probably committed some of a list of crimes.

      --
      Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
    9. Re:!(Prisoner's Dilemma) by uncqual · · Score: 5, Insightful

      If only one twin is responsible for the rapes, how do we know that that the other knows he did them? Maybe all one knows is that he didn't do them and, of course, the other twin who is responsible would likely make the same claim falsely.

      --
      Why is there an "insightful" mod and why isn't it "-1"? If I wanted insight, I wouldn't be reading /.
    10. Re:!(Prisoner's Dilemma) by stymy · · Score: 5, Informative

      How is one lying for the other? Presumably, they are both insisting they are innocent, and one of them actually is.

    11. Re:!(Prisoner's Dilemma) by coma_bug · · Score: 3, Informative

      And the innocent person lacks such a right even in the US.

      wait. what? here is the fifth:

      No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offense to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.

    12. Re:!(Prisoner's Dilemma) by 1u3hr · · Score: 3, Insightful

      If both stay silent, maybe end up with time served 'cause they can't be sure it which of you it was.

      Rubbish. Without proof both must be freed. There is no shared responsibility or punishment. "Unless someone owns up you all go without supper" isn't a legal principle.

    13. Re:!(Prisoner's Dilemma) by iamnobody2 · · Score: 3, Insightful

      "a witness against himself" thats the part you're not understanding there. its perfectly ok to compel him to be a witness against his twin.

      --
      nobody's perfect
    14. Re:!(Prisoner's Dilemma) by chebucto · · Score: 5, Informative

      This is the prisoner's dilemma:

      Two people commit a crime.

      Both are arrested, but there is no physical evidence.

      They are put into separate rooms and each offered a deal:
      1 year in prison for you, and 10 years for your partner, if you admit to the crime first

      If either of them admits to it, they both go to jail - because they both took part in the crime. If they both stay silent, they both go free. However, each has a strong incentive to admit to the crime, because the other person might admit to it first.

      In this case, however, only one person might be guilty. If that's the case, the innocent party has no incentive to rat the guilty one out. The essence of the prisoner's dilemma is lost.

      --
      The English word fart is one of the oldest words in the English vocabulary.
    15. Re:!(Prisoner's Dilemma) by Fishchip · · Score: 4, Funny

      Telekinetically linked? How does that work? Can they move each other around with their minds?

    16. Re:!(Prisoner's Dilemma) by c0lo · · Score: 3, Insightful

      Except the law doesn't work via compromise.

      Ever heard of a plea bargain?

      Not in France, no.

      --
      Questions raise, answers kill. Raise questions to stay alive.
    17. Re:!(Prisoner's Dilemma) by Anonymous Coward · · Score: 5, Insightful

      That's not justice, that's just about the complete opposite of justice. And it's one aspect of being American that I'm deeply ashamed of. There should be no incentive to plead guilty to a crime you didn't commit. The fact that, not only does it happen, but we actually have a name for it should be deeply concerning to anybody to cares about justice.

    18. Re:!(Prisoner's Dilemma) by c0lo · · Score: 5, Informative

      Ever heard of a plea bargain?

      Not in France, no.

      Fine, ever heard of plaider coupable.

      Non. Mais, avec l'aide de l'ami Google, je peux vous montrer quelques informations pertinentes:

      Dans la pratique, cette procédure est surtout utilisée pour traiter rapidement la masse des délits routiers, comme le défaut d’assurance ou la conduite en état alcoolique, ainsi que les délits simples, comme les petits vols.
      ...
      La CRPC n’est toutefois pas applicable à certains délits ou certaines accusations particulièrement graves. Parmi ceux-ci : les violences, les menaces, les agressions sexuelles et les atteintes involontaires à l’intégrité de la personne, pour lesquelles une peine d’emprisonnement d’une durée supérieure ou égale à 5 ans est encourue.

      In english translation - with the help of google, here you have some relevant information:

      In practice, this procedure is mainly used to quickly treat thje majority of traffic offenses, such as lack of insurance or drunken driving, as well as simple offenses such as petty theft.
      ...
      Though, the plea bargain is not applicable to some serious offenses or allegations. Among them: violence, threats, sexual assault and involuntary damage to the integrity of the person, incurring a sentence of imprisonment for a term no less than 5 years.

      --
      Questions raise, answers kill. Raise questions to stay alive.
    19. Re:!(Prisoner's Dilemma) by nitehawk214 · · Score: 3, Insightful

      I assume both twins are guilty. With ovemr a dozen cases it looks like always one was commiting a crime and the other one tried to fabricate an alibi.

      Doesn't change the solution. If both twins are guilty, a detailed DNA analysis will still be necessary to pin the correct crime to the correct twin. You don't get to be convicted just because you probably committed some of a list of crimes.

      Do the DNA test and get the right twin. And the other one goes to jail for perjury and harboring a criminal. Seems a win-win here, and will discourage anyone else from trying this tactic.

      --
      I'm a good cook. I'm a fantastic eater. - Steven Brust
  2. Not an unexpected event.... by rts008 · · Score: 3, Insightful

    I have always wondered what would happen when this type of suspect turned up.(suspect having an identical twin)

    Every set of identical twins I have known, has deliberately used the 'identity confusion' at some point.

    --
    Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
    1. Re:Not an unexpected event.... by Bogtha · · Score: 4, Interesting

      Identical twins isn't the interesting case. It's the conjoined twins that are the real puzzle. Suppose there are a pair of conjoined twins. One is an artist and hates computers, one is a programmer and hates art. Everybody knows this and will testify to the fact. When the artist goes to sleep, the programmer whips out a laptop and hacks into the Pentagon. He gets caught, gets arrested, and admits guilt... what are you going to do, imprison him?

      --
      Bogtha Bogtha Bogtha
    2. Re:Not an unexpected event.... by dissy · · Score: 3, Interesting

      You don't perform just one single sequencing due to the error rate.

      The best way to get the error sigma down is to run 10 or more sequences, however the money allotted only allows for 3 per sample.

      I am trying to figure out how they are getting full sequencing done so cheaply.

      My guess is they are willing to run less sequences and accept the higher error rate due to the smaller sample pool of suspects.
      Knowing one is 70% likely while the other is 30% likely, when they already have claimed only one of these two people could possibly have done it, would likely be enough for a conviction.

  3. Easy solution by Hogwash+McFly · · Score: 5, Funny

    Just charge the one with the goatee.

    --
    Mother, do you think they'll like this sig?
  4. Or IS there even a genetic test?. by popo · · Score: 4, Interesting

    Will someone with a better understanding of genetics please explain how a genetic test is even possible?

    My understanding is that identical twins -- arising from the same zygote -- are genetically identical. Not just "pretty much identical" as the article states.

    What possible "genetic test" is being proposed that could differentiate between the brothers? Is the town being scammed?

    --
    ------ The best brain training is now totally free : )
    1. Re:Or IS there even a genetic test?. by ifiwereasculptor · · Score: 4, Informative

      All joking aside, though, I also got curious. And, as I went to Google College, unlike some underprivileged folks, let me share my inaccessible knowledge: http://genetics.thetech.org/ask/ask68

    2. Re:Or IS there even a genetic test?. by popo · · Score: 5, Informative

      Ah. So there is a way. Thanks for the Google Fu.

      Unlike some 'other' underprivileged folks I have one of those modern "cut and paste" operating systems. :p

      Here is the important bit from the above link:

      "Just like our fingerprints, the environment can change our DNA too. We all build up mutations in our DNA over time. Most of these DNA changes are harmless although some can lead to diseases like cancer.

      Where do these changes come from? Some come from the stuff our body does everyday. For example, we all start out with a single cell and end up with somewhere around 50 or 100 trillion cells.

      The DNA in all of these cells needed to be copied (not 100 trillion times but a lot). The machinery in our cells that copies our DNA is incredibly good at what it does, but not perfect. Occasionally, it makes a mistake that is not fixed.

      Our DNA also changes in response to things like sunlight or the food we eat. Both can damage the DNA causing mistakes to happen.

      Coming up with a genetic test looking for these changes is going to be tough. First, these changes are pretty rare. Everyone has about 100 new mutations in their DNA. Sounds like a lot but spread out over 3 billion base pairs, that is quite a needle in a haystack."

      --
      ------ The best brain training is now totally free : )
    3. Re:Or IS there even a genetic test?. by TheSync · · Score: 4, Informative

      My understanding is that identical twins -- arising from the same zygote -- are genetically identical. Not just "pretty much identical" as the article states.

      Then your understanding is wrong, see this article:

      Geneticist Carl Bruder of the University of Alabama at Birmingham, and his colleagues closely compared the genomes of 19 sets of adult identical twins. In some cases, one twin's DNA differed from the other's at various points on their genomes. At these sites of genetic divergence, one bore a different number of copies of the same gene, a genetic state called copy number variants.

      It is generally felt that copy number variation (CNV) between MZ twins is generally post-meiosis (i.e. mitosis).

      Typical police forensic genetic tests look for a "fingerprint" based on lengths of DNA when cut by particular enzymes. This is unlikely to find CNVs.

      Some CNVs might be discoverable with a SNP microarray chip (not super expensive to perform), but it is possible that you may need to do a complete sequence of both twin's DNA to find the needed CNV differentiator.

    4. Re:Or IS there even a genetic test?. by tibit · · Score: 3, Interesting

      I think that the price indicates they expect to run, about 20 sequencings in total, and I think that's a bit optimistic of them.

      --
      A successful API design takes a mixture of software design and pedagogy.
    5. Re:Or IS there even a genetic test?. by Cyberax · · Score: 3, Informative

      Analysis cost is about $20k per genome for good enough coverage to distinguish CNV (and I work for a DNA sequencing company).

  5. Re:Lock them both up by Anonymous Coward · · Score: 5, Insightful

    How exactly is the innocent one proclaiming his innocence obstructing justice?

    captcha: unproven

  6. Unless French wages are crazy low... by fuzzyfuzzyfungus · · Score: 4, Insightful

    While '1 million euros' is a big scary number(and certainly higher than evidence handling for more prosaic cases), it isn't exactly free to have a bunch of cops go around swabbing at evidence, a judge, some lawyers, a jury, etc. Processing a case, especially a serious criminal case, just isn't inexpensive. Given the existing acceptance of the relatively high cost of justice, it seems strange to wring hands about an abnormally high cost cropping up in an abnormal case.

    Even if justice didn't demand it, it seems like it would be trivially sensible to just quietly pay what it costs to get the DNA analyzed properly, if only to deter others from trying to get cute.

    1. Re:Unless French wages are crazy low... by Fnord666 · · Score: 4, Funny

      it isn't exactly free to have a bunch of cops go around swabbing at evidence, a judge, some lawyers, a jury, etc.

      I'm going to guess that neither the judge, the lawyers, nor the jury were exactly thrilled about being swabbed either.

      --
      'The tyrant will always find pretext for his tyranny.' - Aesop's Fables
    2. Re:Unless French wages are crazy low... by Solandri · · Score: 5, Insightful

      More succinctly, what is the future cost of allowing these two guys to go free to continue his/their crime spree? And what is the cost of all the copycat twins who'll do the same thing once a precedent has been set that the police won't prosecute twins if they can't tell which one did it?

      If that cost is more than the 1 million euro test, then pay for the test.

  7. Re:Lock them both up by Anonymous Coward · · Score: 5, Insightful

    Wow, logic fail. I hope I never see you in a jury...

  8. Re:Just do the damned test by wonkey_monkey · · Score: 5, Insightful

    Perhaps then bill each of them for half the cost, for not cooperating.

    Who says the innocent one isn't cooperating?

    --
    systemd is Roko's Basilisk.
  9. Re:Coercion by Gordonjcp · · Score: 5, Insightful

    ... and that's why those of us in civilised countries consider the US to have a similar legal system to the brutal Sharia law of countries like Afghanistan, Somalia and Mali, among others.

  10. Re:Coercion by shaitand · · Score: 4, Informative

    Here in the Red States of America the prosecution is allowed to specifically threaten you with any ridiculous charges they want to get you to accept a plea bargain. Somehow coercion is allowed for both the police and the prosecution.

  11. Re:Lie Detector Test by nospam007 · · Score: 3, Insightful

    "Another would be to come up with a huge list of possible things that only the criminal would know based on the crimes and quiz them and their whereabouts at the time. Yes, you can lie,..."

    Only morons talk to the police.

    You don't talk to the police.

    Ever!

    It can only hurt you.

  12. Re:Coercion by Anonymous Coward · · Score: 5, Informative

    Whereas in the good, honest Blue States of America, we just threaten hackers for political gain until they commit suicide. Much less expensive.

  13. Budget over Justice? by CB-in-Tokyo · · Score: 4, Insightful

    The justice system shouldn't be haggling over price.

    They have suspects they are sure that did it. They have a method of determining which one, but they are dicking around because of cost?

    Unacceptable.

    1. Re:Budget over Justice? by CB-in-Tokyo · · Score: 3, Insightful

      Option 4.The government pays for the test and justice is served. A million bucks is not a huge amount when we are talking about government budgets.

      You are right though, there is a an amount and a level of certainty where it doesn't make sense to do the test, but a million bucks to keep a serial rapist (or perhaps two) off the streets, would likely pay for itself.

  14. Re:Polygraph and interrogation by SecurityGuy · · Score: 3, Insightful

    Any sympathy for the innocent one? I'd sure hate to be tortured because my sibling committed a crime.

  15. Re:Justice by spire3661 · · Score: 4, Insightful

    When you are wielding life and death IN MY NAME you better get it fucking right. Unjust imprisonment is rape too. Perhaps we should throw some accusations at you and see what sticks, for the greater good, of course.

    --
    Good-bye
  16. Re:Polygraph and interrogation by CrimsonAvenger · · Score: 4, Insightful

    A ball-peen hammer or garden sheers to the knuckles works wonders. Not a lot of sympathy for rapists.

    Of course, only one of them is a rapist. A ball-peen hammer or garden sheers to the knuckles of the innocent twin evokes quite a bit more sympathy....

    --

    "I do not agree with what you say, but I will defend to the death your right to say it"
  17. Re:Coercion by spire3661 · · Score: 3, Insightful

    And then judge specifically asks you if you have been coerced or promised anything and you say 'no, your honor' and everyone in the room winks at each other.

    --
    Good-bye
  18. Re: Justice by canadian_right · · Score: 4, Insightful

    What system should replace the USA system of justice that jails more citizens per capita than any other western nation?

    • For starters:
    • get rid of long sentences for minor drug possession
    • Get rid of elected district attorneys so they can pursue justice instead of elections
    • Get rid of over broad laws with long sentences for minor crimes.
    • Get rid of 'three strikes' laws
    • Get rid of overly long minimum sentences
    --
    Anarchists never rule
  19. Re:Would Someone Explain This? by SocratesJedi · · Score: 5, Interesting

    It sounds a little implausible, but perhaps I am unaware of the forensic issues. Due to massive improvements in DNA sequencing, it costs less than $10,000 to acquire a full genome (see https://www.genome.gov/sequencingcosts/ ). So, back-of-the-envelope:

    (a) $20k to acquire both genomes, plus
    (b) some computational effort to identify interesting DNA polymorphisms ($0 - $1000 ???), plus
    (c) PCR'ing out and sequencing of a region of the crime-scene DNA (cheap; less than $100).

    So $22k, not counting labor costs?

    IAAMB (I am a molecular biologist), but not a forensic one. Maybe it just doesn't work that way. Anyone have other information?

  20. Re:Throw in jail by PhunkySchtuff · · Score: 4, Insightful

    But what if the innocent one has no evidence, or no alibi that will stand up to prove his innocence?
    Then, you're relying on the guilty one to do the right thing and confess so his brother isn't jailed. He's a rapist, do you really want to rely on his good nature?

  21. Re:Throw in jail by slimjim8094 · · Score: 3, Insightful

    If you want to look for the real scum, look for those who would happily put an innocent person to death.

    --
    I have developed a truly marvelous proof of this comment, which this signature is too narrow to contain.
  22. Re:Polygraph and interrogation by Tom · · Score: 4, Informative

    A ball-peen hammer or garden sheers to the knuckles works wonders

    [citation required]

    All the evidence I have seen indicates the opposite. Torture is a horribly ineffective means of finding the truth. In fact, throwing a coin is probably better.

    If it isn't obvious why, the very simplified causation is roughly this: As torture proceeds, the goal of the victim becomes very simple: Make it end, no matter what. We KNOW that people will readily admit to crimes they did not commit under torture, including crimes that carry the death penalty. We know that people under torture reach a point where they would not only say "yes" but also thank you for it if you offered to kill them right then and there. We know that they will invent not only details of the crimes they are being questioned about, but also entirely new crimes.

    We have historic evidence of people admitting crimes under torture where later investigations found conclusive evidence that they could not possible have committed them.

    Torture does not work if your goal is truth.

    --
    Assorted stuff I do sometimes: Lemuria.org
  23. Re:Coercion by cffrost · · Score: 4, Informative

    ... and that's why those of us in civilised countries consider the US to have a similar legal system to the brutal Sharia law of countries like Afghanistan, Somalia and Mali, among others.

    There are those of us in the US who agree that the US legal/penal/justice systems are brutal, regressive, unjust, and counterproductive, and do what we can to change that, but at the same time are opposed by authoritarian-types who claim that various improvements proposed by "bleeding-heart liberals" equate to being "soft on crime." However, my state struck down the judicial death penalty a few years ago and decriminalized marijuana possession last year, so I still have hope that improvements can continue, at least at the state level.

    --
    Thank you, Edward Snowden.

    "Arguments from authority are worthless." —Carl Sagan