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Twist on DNA Privacy
ConfusedVorlon writes "The BBC is reporting the conviction of a man for the murder of a prostitute 15 years ago. The interesting twist is that his DNA was not on record - 'But it partly match[ed] that of a youth's who was known to the police - but who had not been born at the time of the murder. The teenager, it turned out, was a close relative of [the murderor].' There has been concern in the past at the idea of keeping DNA of those interviewed but not charged with crimes. I haven't previously heard of the privacy implications of being related to a criminal/suspect. If you've done nothing wrong, you've nothing to fear?"
This reminds us of a problem with DNA testing: it can't distinguish identical twins or clones. Also, inbreeding might increase the odds for a false positive match, and there may be many other real-world factors we don't know about that increase the probability of a false positive beyond what common estimates would lead you to guess.
These problems are compounded by the widespread misapplication of statistical prodecures in the biomedical sciences (most of the FDA drug testing is based on outdated and basically faulty statistical procedures, and it's probably the same in the forensic sciences).
A recent case here in Canada had me a bit uncomfortable.
A young girl was murdered and police asked Men in the neighbourhood to volunteer DNA samples. About 20 men refused. 19 were innocent and refused for personal reasons. One of these men was eventually implicated in the crime when Police followed these 20 men and picked up "pop cans, et al" used by these men to obtain DNA samples.
This implies - You have no right to refuse to give a DNA sample because one will be taken secretly against your will anyhow.
What happens to these samples? Could I be implicated in a completely separate crime because my second cousin lived NEAR a murder victim who's and had his DNA "stolen" by police?
This can only get scarier without laws to protect us.
The system that the FBI uses to keep track of DNA is called CODIS - Convicted Offender DNA Identification System. It relies on DNA profiling, sometimes called DNA fingerprints.
There are areas in the genome that science currently believes do not contain any genetic information that is actually used. In this "junk" DNA, there are areas called STRs - Short Tandem Repeats. These are places where there is a short sequence of DNA (e.g., ACC) that is repeated n1...n2 times (where n1 and n2 usally range from single to low double-digits.) Since there is (normally) one copy of each gene from each parent, each person will get a section of some length from one parent, and a section of some length from the other parent (the lengths may be the same.)
Glossing over some of the details, and all of the lab work, this means that for each of the 13 loci recognized by the US forensic community (the Brits use a slightly different set) an individual will have 13 pairs of numbers. For each loci, each number has a different frequency, so it is possible to build up a likelihood (i.e., chance that the DNA came from a person other than the person in question.) These numbers get much, much larger than the number of people on the planet for full profiles.
Identical twins will have the same numbers. Children have one number from each of their parents. Siblings are likely to share numbers. Two unrelated people may have some numbers in common.
This is how paternity test are done. (The child will have one number at each loci in common with the father.)
This is how rapists are linked to victims. (Their profile matches exactly with DNA from semen, skin under fingernails, blood from the scene, etc.)
This is how people behind bars are cleared of crimes. (See above.)
This is how many of the victims of the World Trade Center attacks are being identified. (By matching DNA from victims' toothbrushes, razors, hairbrushes, dirty clothes, etc. to the DNA of the body parts found at the site; and also by kinship analysis.)
I have been falsely arrested twice. These two "false arrests" are on my record from my childhood. I'm now 29. Every 3 years I make "total information requests" from everyone from whom I can think of that collects information from me. (credit, mail, email, post office, clubs, memberships, utility, etc)
One interesting thing is my complete "litigation/arrest" history. Essentially my file that the FBI would "examine".
I find it unfair that my peeping tom arrest from 18 (false arrest) & my theft from Walmart at 22 (false arrest) are still even capable of being associated with me. Also, every traffic ticket I have ever gotten, every court case I have been involved in; are all on an easily accessed file. If I were ever accurately arrested for an associated offense, wouldn't I then have a pattern? Even though wiped from my record or not guilty?
For the peeping tom incident I was handcuffed, made to take a lie detector test (failed), and kept in custody for 4 hours from 11pm to 3am. It wasn't until my girlfriend came in and said she was with me and that I wasn't doing it, that I got off. It was all because the next door neighbor girl was jealous of my having a girlfriend.
Yell & scream & rant & rave... it's no use... you need a shaaaave ~ Bugs Bunny
Suspects are instrumental in convicting themselves using the very information they volunteer to the police. An almost as well time honored tradition as good cop bad cop is lying. Police lie all the time to pressure suspects into convictions: "we have witnesses who saw you do it", "your partner is ratting you out right this second", "you're only making this harder by not cooperating".
Don't just take my word for it--watch NYPD Blue. These aren't the corrupt cops. These are all cops (with admittedly better makeup and prettier precincts). What they do is perfectly legal.
If the police are speaking to you, it means they do not currently have the evidence they need to convict you. Otherwise they wouldn't even waste their time. Under no circumstances should you talk to them without a lawyer by your side.