Expert Evidence And The Judge As Gatekeeper

For expert evidence to be admissible, it must be: (a) relevant; (b) necessary to assist the trier of fact; (c) it must not be subject to any exclusionary rules; and (d) the expert must be properly qualified (R. v. Mohan).

Earlier this month, in Meady v. Greyhound Canada Transportation Corp.,  the Ontario Court of Appeal examined a trial judge's decision to exclude expert evidence for failing to meet the second requirement of necessity. The Court of Appeal ultimately upheld the trial judge's decision and noted in its reasons that there has been a growing recognition of the responsibility of the trial judge to exercise a more robust "gatekeeper" role in the admission of expert evidence.