Author: Keith Marlowe KC

Expert evidence plays an increasingly important role in modern civil litigation. In many disputes, the outcome may turn largely on the opinions offered by expert witnesses. This paper explores the governing framework for expert evidence, including the Mohan threshold requirements and the court’s gatekeeping role; common admissibility challenges such as relevance, necessity, qualifications, reliability, and independence. It also highlights practical strategies for raising objections efficiently in interlocutory settings and at trial, including when the challenge should be directed to admissibility versus weight.

These materials are part of a collection presented at LESA’s Evidence Refresher program in Edmonton on April 23, 2026.