Monday, December 23, 2013

Agreement expert qualified to give opinion evidence does not add weight to expert's opinion

R. v. Strickland, 2013 NLCA 65:

[18]        The issue regarding expert evidence as argued on the appeal did not extend to all aspects of the test for admissibility of expert evidence as set out in R. v. Mohan1994 CanLII 80 (SCC), [1994] 2 S.C.R. 9 [1994] S.C.J. No. 36 ("R. v. Mohan").   R. v. Mohan requires the trial judge to consider four criteria: (i) relevance, (ii) necessity in assisting the trier of fact, (iii) the absence of an exclusionary rule, and (iv) a properly qualified expert.  It was criterion (iv), whether Constable Emberley was a properly qualified expert, on which the trial judge questioned whether he should enter into a voir dire.  Defence counsel waived the voir dire stating "we won't object to him being qualified as an expert witness for the same reason he's been qualified as an expert witness in the past."

[19]        That consent by defence counsel was stated by the trial judge to have added significant weight to Constable Emberley's testimony.  With respect the attribution of "significant weight" to that factor was an error of law.  Defence counsel's consent to the qualification of the proposed expert witness was addressed solely to admissibility of the expert evidence and could not reasonably be interpreted as an acknowledgement by defence counsel that such evidence should be accorded weight beyond what the trial judge should otherwise attribute.  The weight to be attributed to expert evidence must be determined by the trial judge having regard to the reasons given for the expert opinion, the evidence bearing on the basis of the expert opinion and the extent of the expert's expertise.  Defence counsel's consent does not add weight, much less significant weight, to the expert evidence.  See –Alan Mewett and Peter Sankoff,Witnesses, loose-leaf, (Toronto: Carswell, 1999), Chapter 10 at page 47.  The error by the trial judge was an error of law as he applied an improper factor in the assessment of evidence.   

1 comment:

Kas Marynick said...

Caveat: I didn't read the decisons, but this has the signs of the all-too-familiar scenario in which a trial judge hangs a verdict on a judgment call made by counsel in the course of a complex trial. I'll keep this one in my bag for when I'm chided for making too few concessions. Thanks James!