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114 MANITOBA LAW JOURNAL |VOLUME 35 NUMBER 1
DNA model. In particular, concerns over the statistical validation of particular
forensic techniques and over the trial presentation and interpretation of match
statistics seem likely to come to the fore should the DNA model be applied more
broadly.
In the Manitoba context, DNA evidence and how it should be interpreted is
a current subject due to the high profile trial of Mark Edward Grant for the 1984
murder of Candace Derksen. 9 Questions about the interpretation of DNA, other
forms of forensic evidence, and the jury charge have formed the basis of his
appeal of his conviction. 10 While DNA evidence has largely become routine in
Canadian courts, R v Grant demonstrates how concerns over the use of relatively
marginal DNA samples allow the defence to unpack the technique itself and
questions about the limits of technology, expertise, and interpretation come to
the fore. 11 While this paper will argue that DNA is likely becoming the model that
all other forensic techniques will have to follow, it is important to keep in mind
that it, like all other forensic techniques, remains only circumstantial evidence
that must be interpreted by the fact-finder in the context of a trial.
The following paper will start by describing the recommendations made by
the National Academy of Sciences Committee and how, if implemented, these
recommendations would result in a change in the scientific approach or paradigm
used by forensic science generally. The second section of the paper will introduce
DNA evidence and the scientific controversies that were current during the
period that Canadian courts were first evaluating its admissibility. The third will
describe some of the early Canadian DNA jurisprudence to identify some of the
difficulties Canadian courts had when confronting these controversies. The
concluding section will discuss how this experience with DNA could help identify
potential difficulties with post-NAS Report forensic science.
III.
THE NATIONAL ACADEMY OF SCIENCE’S REPORT ON FORENSICS
This section will show how the NAS report argues for major changes in the
way forensic science is practiced and how the Report proposes a series of
recommendations aimed towards specific forms of forensics. It will argue that the
factor that links these recommendations is the use of DNA as a model and that,
taken together, the NAS recommendations argue for making all forensic science
9
10
11
James Turner, “Schoolgirl trial awash in DNA testimony”, online: CBC News .
R v Grant, Notice of Application of Leave to Appeal and Notice of Appeal.
“Faulty DNA testing attacked at murder trial”, online: CBC News
,
“DNA doubted at murder trial”, online: CBC News .