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LEGAL REPORT: FORENSICS electric current to drive negatively charged molecules, including both DNA and contaminants, into a gel in a lab vessel. Rotating electric fields are applied to the gel to concentrate the DNA at the gel's centre. That is extract- ed for analysis. "By exploiting the physical traits of DNA — electric charge, length, and flex- ibility — we've been able to extract DNA from samples that would otherwise not produce enough clean DNA for analy- sis," says Marziali. That clean DNA, says Prevett, can then be subjected to stan- dard DNA analysis techniques. Marziali says extracting DNA by conventional methods — which rely on the molecules' chemical properties — is challenging when there are only trace amounts of DNA or when the source sample has contaminants with similar chemical traits. "We've found that DNA and RNA respond to electric fields in a way that is very different from other molecules," says Marziali. "By exploit- ing this unique property, we were able to extract high-quality DNA from a highly contaminated sample from the Athabasca oilsands." And, the team successfully tested the technique on samples provided by the RCMP, confirms Fourney. He says the RCMP had advance warning that "a new and exciting technology was around the corner," calling it a promising step for- ward in intelligence-led policing. The process, he says, is "potentially useful for more challenging samples." But, Fourney cautions, there are steps police need to take before SCODA can be definitively added to the police tool- box and used in the charge-approval process, and prosecutions. "We would vigorously validate this, many more samples . . . how it would operate in the real world," he stresses. "This is very exciting. The silence of the grave is a poetic anachronism. Volumes can be spoken to those who will listen, and this is one of those situations." And, Fourney says, with a climate such as Canada's, that real-world valida- tion means seeing how SCODA will be useful on DNA sources that have been frozen and thawed, which can break down the nucleic acid. The problem right now, he notes, is the SCODA sys- tem is slow, each sample taking half an hour to run. It's a shortcoming Marziali and his team are working on. He wants to move that rate to 48 samples an hour. Fourney says the current magnetic bead-extraction process, which is less efficient at producing clean samples, can process 96 samples at once. What's more, the process must leave the extracted DNA open to the possibil- ity of replication so other labs can also examine it. The leading bead-extraction pro- cesses are marketed by Promega Corp. and Qiagen. Marziali hopes to eventual- ly replace those methods with SCODA. But, adds Prevett, that whole validation process needs to be verified as accept- able in the chain-of-evidence process before a court. "You have to be careful that the end result will do what you want it to." Fourney agrees. "It would have to be peer-reviewed and validated by the The evidence is clear McWilliams' Canadian Criminal Evidence, Fourth Edition Renowned as the authority, McWilliams' Canadian Criminal Evidence, Fourth Edition, also available online, offers an understanding of how the rules operate at the admissibility stage and when judges come to deal with evidence either in their reasons or in the charge of the jury. It includes the perspectives of criminal law experts from the bench, bar and academia. Looseleaf & binders (2) • $429 • Releases invoiced separately (2-3/yr) • P/C 0496034000 • Vol. 1/2 ISBN 0-88804-371-6/-442-9 Cox's Criminal Evidence Handbook, 2009 - 2010 edition This book codifies the whole body of criminal evidence in one convenient resource. Inside you'll find all of the cases that have shaped the law of evidence. Each point of law is summarized as a precept, followed by a list of relevant case law so you can review an entire topic in a matter of seconds. Hardbound • 724 pp. • June 2009 • Standing order $105 • P/C 0265140999 • Current edition only $115 P/C 0265010002 • ISSN 1201-253X Also available! Forensic Evidence in Canada, Second Edition Hardbound • 652 pp. • 1999 • P/C 0281010002 • $159 • ISBN 0-88804-300-7 For a 30-day, no-risk evaluation call: 1.800.565.6967 CA007 Canada Law Book is a Division of The Cartwright Group Ltd • Prices subject to change without notice, to applicable taxes and shipping & handling. 40 NO VEMBER / DECEMBER 2009 www. C ANADIAN Law ye rmag.com CA007 (CL 1-2h).indd 1 CL1109 10/28/09 10:40:43 AM The H Contributions from academics and practitioners including Professor Benjamin L. Berger, Nikos H onourable Justice S . Casey H H arold J. Cox, Gregory Lafontaine and Vincenzo Rondinelli ill, Prof. David M. Tanovich and Louis P. S trezos (General Editors) arris and Professor Ronalda Murphy Editor- in- Chief: Gary Chayko; Associate Editor: Edward Gulliver