The testimony of an expert witness can be instrumental in proving liability or damages in a case, but only if they are carefully selected and adequately prepared for trial.

Two experienced panelists provided concrete tips for how to do just that, from the points of view of both litigation counsel and expert witness, at a lively and interactive CLE session held in Dublin on Tuesday.

Simon Potter, partner with McCarthy Tétrault in Montréal, discussed how to research, select and retain a credible and effective expert, noting qualities such as reputation, qualifications and the track record of previous reaction of the courts to his or her testimony.

Potter emphasized the importance of a carefully written initial mandate letter, making it as clear as possible what the witness should be prepared for. At trial, he said it can usually be assumed that the judge has read the expert report, so the focus should be on thorough preparation for cross-examination.

Bob MacDonald, a Chartered Accountant with Navigant Consulting, provided the expert witness perspective and commented on the duty to be thorough and unbiased, including techniques for how not to be pigeonholed by only the direct questions posed at trial.

Potter also commented on the emerging trend that is seeing less deference being given to expert witness testimony, with courts stating that such witnesses are there simply to clarify technical or specialized concepts, rather than advance the case for litigation counsel. He called on all trial lawyers and the CBA to address this issue in the interests of the legal profession.

Have your own experiences to share regarding the use of expert witness testimony? Post your comments here…