JohnLloydScharf

Tue, 02 Dec 2008 22:18:47 -0500

In the CODIS database of Maryland , of fewer than 30,000 profiles, 32 pairs matched at nine or more loci. Three of those pairs were “perfect” matches, identical at 13 out of 13 loci. Experts say they most likely are duplicates or belong to identical twins or brothers, but they did not establish that. A study of the Arizona CODIS database carried out in 2005 showed that approximately 1 in every 228 profiles in the database matched another profile in the database at nine or more loci, that approximately 1 in every 1,489 profiles matched at 10 loci, 1 in 16,374 profiles matched at 11 loci, and 1 in 32,747 matched at 12 loci. In a recent case against a Murillo-Sosa, a jury was told the match was 5 of 13. They had to say he was not guilty. SO, what kind of matches are they making? Everyone talks as if DNA evidence is absolutely reliable, but it isn’t. The DNA profiles usually prepared only use part of our DNA. Most of the time this level of DNA fingerprinting is accurate enough to identify an individual – but things can go wrong. Raymond Easton suffers from Parkinson’s disease and by the year 2000 he was so disabled that he could hardly manage to dress himself without help. In spite of this he was charged with a burglary which had taken place 200 miles away from his home! The error arose because three years earlier Raymond had been involved in a family dispute. He had been cautioned and a DNA sample was taken. By an amazing coincidence, Raymond’s DNA matched that found at the scene of the burglary. Fortunately DNA testing offered a way out of the situation it had created. Once a fuller DNA analysis was made, differences between Raymond’s DNA and that of the burglar became clear and the charges against him were dropped. Despite its increased power, DNA profiling is often not enough. “Wrongful convictions can only be made if DNA is looked upon as the only evidence,” noted Mark Benecke, one of Europe’s leading consultant forensic biologists,based in Cologne, Germany. According to Benecke, the integration of different sources of forensic evidence and their combination with investigative and legal procedures are even more significant than progress in any single field, such as DNA testing.

Bostonist: Boston Blotter: BPD Makes a Clutch of Arrests

JohnLloydScharf