Micah's DNA (Photo credit: micahb37)
By Bob Barney-The Plain Truth
The Plain Truth has uncovered shocking evidence that DNA convictions and acquittals just may be largely based on junk science and downright fraud. In case after case, we have documented hundreds of cases of unreliable DNA findings, which for the most part, most Americans have been led to believe that DNA evidence was rock solid. Shockingly it isn't!
According to this report by New Scientist DNA is largely considered to be the gold standard in forensics. If a suspect's DNA is found at the crime scene, it is compelling evidence for a conviction. But how is a DNA match determined? There are many places in our genetic code where there are short sequences that are repeated over and over. These repeated regions are called short tandem repeats or STRs. The places where these STRs occur are called loci. There are many variations in the lengths of STRs (I may have 5 repeats at a particular loci and you may have 8 ) and by looking at many different loci scientists create a kind of profile or human bar code that is unique to each individual. This technique is also used to determine parentage because you inherit half of your unique barcode from your mother and half from your father.
So where is the problem in this technique? After scientists analyze the DNA found at a crime scene, they compare it to the suspect's DNA to see if their barcodes match. The more loci where the STRs match, the more likely that the DNA comes from the same individual. Typically, to make sure that the barcodes matched, labs in the United States look at 13 loci. Labs in the United Kingdom look at 10 loci. If all 10-13 loci had the same lengths of STRs, it was said that the DNA was from the same individual. The lower the number of loci, the less confidence the DNA is a match. In other words the longer the barcode, the better the identification tool.
The problem comes from the fact that most DNA from a crime scene is not perfect. It can be degraded or mixed with DNA from other individuals. Sometimes labs can only match 9 loci to the DNA found at a crime scene.
Scientists are starting to question this assumption that 10-13 loci are enough to rule out the possibility of a random match to DNA other than the suspect. In other words, if 10-13 loci are not enough to make a definitive barcode, then a 10-13 loci DNA profile can actually match more than one individual. According New Scientist, a recent look into the possibility of random matches produced some serious results:
The first clue that something might be amiss came in 2005, when limited data was released from the Arizona state database, a small part of CODIS. An analyst who compared every profile with every other profile in the database found that, of 65,493 profiles, 122 pairs of profiles matched at nine out of 13 loci and 20 pairs matched at 10 loci, while one pair matched at 11 loci and one more pair matched at 12 loci. "It surprised a lot of people," says signatory Bill Thompson of UCI. "It had been common for experts to testify that a nine-locus match is tantamount to a unique identification."
So in a sample of 65,000 profiles, 122 profiles matched at 9 loci, 20 profiles matched at 10 loci, and 1 profile matched at both 11 and 12 loci. According to Bill Thompson, experts have testified that 9 loci is enough for a unique profile. This comparison calls into question the assumption that 9-13 loci are enough to definitively match a suspect's DNA to that found at a crime scene.
The problem is that a search of the news databases show a trend of wrongful convictions by DNA evidence.
ABOUT 60 convicted criminals could have their cases reopened amid claims the DNA evidence used to incriminate them was unreliable.
Ron Grice, a former Queensland Health Scientific Services scientist, said he was haunted by memories of submitting potentially unreliable DNA evidence to the courts. He believed about 5 per cent of the 1200 cases he had handled relied on samples too small to be retested.
Mr Grice yesterday attacked the culture of the QHSS, saying it was not uncommon for he and his colleagues to mix up DNA samples belonging to different cases. Despite the existence of internal errors, he said, QHSS encouraged him to record DNA test results to be used by the courts, even if the samples were too small to be retested.
"When I was at the John Tong centre, quite often we used to put our own blood as controllers and quite often my (colleague) would walk down the aisle and say, 'I've just committed another rape at the Gold Coast'," Mr Grice told a DNA forum at Griffith University on the Gold Coast yesterday.
"If you can't resample and you can't retest, you say an internal error might have occurred and we can't possibly send this bloke to jail. Time and again, our samples are so small they could not possible be retested - I used to do it myself and it still gives me nightmares when I lie in bed.”
"You'd go off to court and argue yes, you found an incriminating bit of DNA on a particular item, when really you couldn't resample the item and you didn't even have enough samples to retest."
Mr Grice said he tested about 120 cases a year, of which he feared about 5 per cent relied on samples that were too small to be retested.
Despite his concerns, he did not voice them in court, partly because defence lawyers did not have enough forensic knowledge to ask about the testing procedure, and partly because QHSS wanted results, even if the samples could not be retested.
Police Commissioner Bob Atkinson yesterday defended the practices of the state's forensic scientists but said cases documented by Mr Grice should be re-examined.
A forensic sciences spokeswoman at QHSS yesterday confirmed that it continued to supply DNA test results to the courts, even if the samples were too small to be retested. But she said processes were in place to prevent miscarriages of justice.
WHEN a defendant's DNA appears to match DNA found at a crime scene, the probability that this is an unfortunate coincidence can be central to whether the suspect is found guilty. The assumptions used to calculate the likelihood of such a fluke - the "random match probability" - are now being questioned by a group of 41 scientists and lawyers based in the US and the UK.
In case after case, reputable news sources are reporting convictions based on DNA evidence that simply is junk science. The Plain Truth asks the question, is DNA testing a government hoax? Keep watching the news, and do some web searches for yourself, and we think our readers will have their eyes opened!
Here are just a few: