Wednesday, May 7, 2008
On three previous occasions (here, here, and here), I have written about the U.K.'s controversial use of low copy number DNA, which allows the genetic profiles of suspects, victims or witnesses to be "uncovered" even when there is only a tiny amount of biological material present, sometimes as small as a millionth of the size of a grain of salt). The U.K. first suspended use of low copy number DNA, but then controversially reinstated its use based upon a (politically motivated?) report finding it to be scientifically valid. That decision was controversial because low copy number DNA has been consistently doubted in the scientific community, leading to it only being used in the U.K., the Netherlands, and New Zealand.
Well, in the wake of the U.K. experience, it looks as if New Zealand is primed to hear a challenge to its use of low copy number DNA. Last August, Michael Scott Wallace was found guilty of the murder of German tourist Birgit Brauer in September 2005. Allegedly, on September 20, 2005, Wallace picked up the 28 year-old Brauer as she was hitchhiking and then drove her to Lucy's Gully, where he bludgeoned her with a metal bar and dragged her bleeding body into the bush. According to the State, Wallace then stamped on Brauer's neck and unbuttoned her jeans with sexual intent, but was spooked by a passing car and plunged a knife through Brauer's heart. Brauer's body was later found by a jogger who saw drag marks leading into the bush.
Among other evidence, there was a small amount of biological material found on a metal bar linked to Wallace's vehicle, which forensic scientists determined likely belonged to Brauer based upon the use of low copy number DNA. Wallace's lawyers now plan to appeal his guilty verdict, using the U.K.'s recent history with low copy number DNA to argue that this evidence should have been inadmissible at trial. Based upon the paucity of countries using low copy number DNA and the troubles that have arisen with its use, I think that they have a very good argument.