if the woman in the swab making lab really is a serial killer - one for CSi I think
A 16-year hunt for a mysterious female serial killer by German police has seemingly ended in farce, as officials admitted they now believe a trail of DNA from 40 crime scenes could have been left by contaminated swabs. In 2007 authorities put up a €300,000 reward for information about the so-called "Phantom of Heilbronn", …
Like the mistake last year in Australia (which, commendably, the authorities addressed quite rapidly and openly) this may help provide perspective to the claims of infallibility that have been made of this technology.
"A photofit released last year, based on a witness description, had male features, prompting press speculation the Phantom could be a transsexual"
ODFO, surely someone with more brain capacity than roadkill would not jump to the transsexual conclusion and would draw a more rational theory.
Bloody press always picking the most extreme option to make stories sound interesting.
I love the fact this country keeps getting dumber, it makes me look even more smarter
Unlike. say, fingerprint evidence, us ordinary mortals can't see DNA evidence for ourselves. Instead we have to rely on the officers, scientists, analysts (and now it seems, swab manufacturers), to all do their job dilligently and honestly. In the end we just have to believe what they tell us.
Without it,, they would (rightly) have investigated many crimes as totally unrelated, and likely solved some of them.
I've now looked at earlier press reports and wish I'd read about this much earlier. Hindsight is a wonderful thing, but I'm convinced I'd have realised the truth without it.
Apart from the DNA there was ample evidence that there was no serial killer/criminal.
[Sherlock Holmes] Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth. [/Sherlock Holmes]
A: ... Not Very
Science 101 - Do your experiments and have a control sample. Don't just look for evidence that proves a theory of guilt - look as hard for evidence that disproves your theory.
Alien ? - We only test delusional country bumpkins to prove how clever mankind has become before the invasion .
Contamination of DNA samples in a major issue. The original developer of the technique had problems with contamination and he was using well trained post-graduate students. The average laboratory for DNA testing is NOT staffed by PhDs...
Another issue is the statistics presented. A zero match would be enough to prove innocence but a 99.99% match doesn't prove guilt (even your brother will have a better match to you than that.) None of the studies I'm aware of have done exhaustive sampling within family, racial, and geographic groups.
Sarah ,Sarah, you should know by know some thing just fly over peoples head. I mean you have seen how some people don't get jokes unless you tell them its a joke. Sarcasm ?? Tha'ts an undefined sub routine
Oh and Sarah you owe me a new keyboard. While I know you were joking I know two MtF TS that work swat. :). So that comment made me spit wine all over my monitor and keyboard
Aren't these meant to be almost as rare as the proverbial rocking horse droppings?
Would not the logical course be to run some tests from each batch of swabs with nothing added to them but some distilled water to wet them? They *should* all read empty. If not the politzei have got a problem.
Mines the one with "He who fights monsters" in the pocket.
The swabs are cotton buds, apparently the same as the ones sold in millions for domestic use. A product you'd expect to be sterile. With modern mass-production techniques I can't see any reason for any to be contaminated
Contamination is only a hypothesis at present, but it's a hypothesis that makes a load of problems
disappear. Best example of Occam's razor I can recall.
It isn't just DNA evidence that been discredited but criminal profiling. There was a wonderful article in The Mirror last November, http://tinyurl.com/c3dlr2
"Interpol and police computer checks built up a picture of a junkie, wandering across Germany killing at random for petty cash to feed her drug habit.
Psychiatrist Kurt Kletzer, who profiled incest monster Josef Fritzl said: "Like Fritzl, she is able to project an aura of normalcy while being anything but. She is compelled to murder to feed her habit, thus reducing the victim to the status of a worthless object.
"These psychopathic traits would have been formed at a very early age.
I would venture that the police are looking for someone from a damaged home life, perhaps a foster child or orphan, a child who was abused or whose carers were addicts.""
"Another issue is the statistics presented. A zero match would be enough to prove innocence but a 99.99% match doesn't prove guilt (even your brother will have a better match to you than that."
No match does not mean not guilty, it could mean several things:
- The sequence you're looking for in the DNA isn't present - try a different sequence.
- The DNA has been degraded with DNAse, and there's basically nothing left to identify.
- The person still comitted the crime, but this DNA isn't there's - find more samples!
And it doesn't work in a percentage-wize fashion. You wouldn't use inclusive matching to prove/elmininate a suspect, you would be exclusive - ie, you are either the person whos DNA this belongs to you or not. If the results aren't clear enough, then the lab will say so. They won't speculate.
(Fortunately, criminals leave more than enough DNA at the scene of the crime, which leads to very confident results, especially if the victim put up a fight - grow you're fingernails people!)
Your brother's DNA will be 99.99999% similar, but at the end of the day so is a chimps.
As you're only interested in that 0.000000001% difference, then you are technically only 50% similar (statistically) to your brother (50:50 chance of getting the same chromosome from your mother/father that your brother did) when it comes to the DNA that matters.
And if those odds arn't good enough for you, there are a whoooole bunch of other tests.
You can roughly tell a person's age from there telomere length, so if the brother is 60 and the suspect is 18, it will be very obvious that it isn't him - but a good DNA fingerprint test (which i assume you would use if someone's life is hanging on the results) will look for something in the sample that only one in a billion people will have - and perentage has nothing to do with it.
Just the random errors cells make when they undergo mieosis. These DNA replication errors are totally random.
Anyway, the point i'm trying to make is that DNA fingerprinting IS reliable and very effective if done correctly. You can't say that as 6 perps havn't been caught by fingerprinting, then the whole technique should just be dropped. It *has* caught hundreds of thousands of guilty people, and cleared thousands of other-wize convictable innocents.
Besides, it's not the technique that convicts people - a jury does that based on the evidence.
If they tried to convict someone who's DNA had appeared positive due to contamination, it would be quite obvious something has gone wrong.
"We found your DNA on the kitchen knife that killed your wife, and your family car which could have been used to transport the body was covered in it. A spade in your shed also contained your DNA, which could have been used to bury the victim's body."
"We also found sink and drain unblocker in your sinks and drains, presumably so you could eliminate the DNA evidence. What's more, our detectives noticed that you have Sky+ and have recorded several episodes of CSI Miami, dating as far back as season 1 recorded in 2003 - suggesting you have been planning the murder of your wife for at least 6 years..."
Forensics doesn't work like that. DNA fingerprinting is worthwhile, and really is very very accurate providing the source is of good quality.
So rest assured people, no one is going away for a crime they didn't commit simply because a lab assistant labeled a test tube incorrectly. If that ever does happen, a lab would quickly loose it's licence and go out of buisness when the inevitable re-trial comes around.
So i reiterate - grow your nails people!! xD
The BBC has now reported that the DNA has been traced to a Bavarian factory worker.
"One company making swabs said they were not intended for analytical, but only medical use, while another said that there had been no requirement for the swabs to be free of DNA."
The point is not so much whether the underlying science is valid, it is the way that it comes to be used in practice.
The case of Shirley McKie illustrates quite clearly the "obdurate and arrogant stance" that had developed in the Scottish fingerprint service. (http://news.bbc.co.uk/1/hi/scotland/4967160.stm)
The case of Barry George illustrates how forensic tests can be over-rated or possibly misused.
The 'one in 73 million headline' in the case of Sally Clark illustrates how statistics can be misapplied.
In each of these cases it was "quite obvious something ha[d] gone wrong" once the evidence was more properly examined, yet innocent people's lives were seriously damaged. The so-called 'prosecutor's fallacy', which you dismiss with your sketch, remains a significant feature of the criminal justice system and shortcomings in the use of DNA profiling do little to remedy it.