Law Times

PAGE 12 Criminal bar worried about accuracy of DNA testing FOCUS the legal community as well as science watchers. Claims of con- taminated results due to subjec- tivity and bias caused a stir at the recent Symposium on DNA Forensic Evidence in April and are continuing to give criminal lawyers food for thought. Until A thought of DNA testing as be- ing immune from subjectivity and bias. As recently as 2009, the U.S. National Academy of Sciences produced a report on the state of forensic science that criticized many of the methods then in use and held up DNA testing as the gold standard. A report published in late 2011 by Itiel Dror of the University Col- lege London in Britain and Greg Hampikian from Boise State recently, many have BY JUDY VAN RHIJN For Law Times new scientific report that throws doubt on the efficacy of DNA testing is shaking up University in Idaho has since castigated that position. It describes the results of an experiment in which 17 North American DNA ex- aminers provided their in- terpretation of data from a real criminal case involving a mixed sample from a gang rape. In the real case, two examiners had found that a match was "not excluded. Unlike the experts involved in the case, the 17 examiners had no contextual informa- tion about it. They were all working from the same ac- credited governmental labo- ratory, thereby removing the influence of varying proce- dures and environments. Not only did the 17 analysts " sions. One examiner concluded that the suspect couldn't be excluded and four came back produce inconsistent interpre- tations, the majority of context- free experts disagreed with the laboratory' s pretrial conclu- have subliminally interpret- ed ambiguous information in a way that was helpful to the prosecution even though they didn't consciously real- ize what they were doing. Al- though there has been some criticism from the scientific community of the leap made to reach this conclusion, the variability in the results alone is causing concern in many circles. David Rose of Neuberger 'Every scientist should be subject to some form of double-blind testing to find out what their accuracy rate is,' says David Rose. with inconclusive. A further 12 examiners came back with ex- clude. Dror and Hampikian sur- thought the original pair may the varying results. They nificant and definitely not good news. "It should be amplified and looked upon with concern. It will certainly open up a new perspective when it comes to fo- rensic DNA practice. He suggests the report is sig- "Secondly, extraneous informa- tion can affect an expert' mised that the difference in contextual information given to the examiners was the cause of says the issue now is that DNA mixture analysis is subjective and may be subject to bias. "I've always said that forensic science was tainted by error. Now we have evidence. Lawyer Ricardo Federico " Rose LLP believes the authors came up with two interesting observations. "Firstly, if ev- ery examiner is not going to come up with the same result, there is subjectivity, " he says. s result." the experiment didn't use a large sample, the study demonstrates the possibility of human error where low numbers of template molecules are amplified and complex mixtures are analyzed. "DNA testing might be the gold standard for clean, single, un- corrupted samples when com- pared with a clean, uncorrupted sample from a database. Even in relation to complex cases, DNA testing is still far superior to ev- ery other kind of testing, but we have to understand that there are limitations." Previous research in relation Rose points out that while " to other methods of identifica- tion, such as fingerprints, writ- ing samples, toolmarks, bite marks, and other specimens, suggest that contextual influ- ences are most powerful when the evidence is ambiguous and complicated. "When the data is clear and decisions are simple, then the power of context is di- minished, quotes British DNA expert Pe- ter Gill as saying: "If you show 10 colleagues a mixture, you will probably end up with 10 different answers." "The thing about DNA is that it's a unique form of identi- " the report noted. It fication," says Rose. "Each case is different. For the majority of single samples, it wouldn't be a problem." The study raises questions about the extraneous informa- tion analysts receive. If medical researchers design their drug trials to be blind, lawyers and others may wonder why scien- tists don't do the same. "To what extent do they get it? Why do they need that infor- mation at all?" asks Federico. Rose explains that analysts ACCELERATE YOUR SUCCESS GET THE FULL PICTURE OF THE LAW WITH WESTLAW® CANADA EFFECTIVE RESEARCH PATHWAYS Experience seamlessly integrated research that's illuminating and efficient, not confusing and frustrating. All Westlaw Canada content is seamlessly linked so you never have to back track to find related information. You'll find everything you need in one place. We'll point out and provide links to relevant related material along the way. This logical linking ensures that your research is always moving forward, giving you the fastest route to better results. Get Better Results Faster with Westlaw Canada Call 1-866-609-5811 or visit www.westlawcanada.com routinely receive background information from a submission document sent with the sample that starts things off at the lab. "The police describe the offence and who is being examined. The amount of information varies." He refers to the effect of this as "the Queen of England syndrome. profiles and are told that one matches the archbishop of Can- terbury and you know he was having tea with the Queen of England at the time of the of- fence, would you still call it a match?" Federico wonders whether a test that's really a science ques- "If you are given two DNA " July 23, 2012 • law Times tion can be done without con- textual information. "The an- swer seems to be yes. It seems to me the scientific community has no business in the contex- tual side. In my opinion, testing should be done in a contextual See New, page 13 www.lawtimesnews.com

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