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Canada's Use of Expert Witnesses and Scientific Evidence Admissibility

NCJ Number
220976
Date Published
July 2006
Length
21 pages
Author(s)
Jeff Chesen
Agencies
NIJ-Sponsored
Publication Type
Legislation/Policy Analysis
Annotation
This paper examines the use of expert witnesses in Canada, and the development of scientific evidence admissibility in the Canadian courts.
Abstract
Canadian courts have determined that evidence and testimony should be examined on a case-by-case basis. This threshold was set because of the inherent danger that expert testimonial evidence could be misused to distort the fact-finding process. Dressed up in scientific language which the jury does not easily understand and submitted through a witness of impressive antecedents, expert testimonial evidence is likely to be accepted by a jury as being virtually infallible and as having more weight than it deserves. Canadian courts, like their American counterparts, have been enthusiastic in their acceptance of expert testimony in most scientific areas. A series of cases have set forth the new parameters for admission of expert evidence. The seminal Canadian case, R. v. Mohan established a similar ruling to that in the American case Daubert v. Merrell Dow Pharmaceuticals, Inc., that expert evidence must be based in science. This has led to the admissibility of DNA evidence in Canada, and the recent exoneration of Gregory Parsons, David Milgaard, and Guy Paul Morin, all of whom of who were wrongly convicted for crimes they did not commit. The cases shared many common traits: each was erroneously convicted of heinous crimes and spent time in prison; in each case, the individuals maintained their innocence; and for each of them, DNA evidence overwhelmingly cleared their names. Since then, some parameters and guidelines for expert testimony have been codified. The admissibility of expert witnesses has been addressed in amendments and additions to the Alberta Rules of Court. The new rules add many more detailed requirements to be satisfied before the court will receive expert testimonial evidence. They also encourage the parties to an action to agree to the uncontested admission of all or part of the expert evidence, with strict sanctions for unreasonable objections. References
Date Created: January 10, 2008