5. Novel and Challenged Science

• Author: David M. Paciocco - Lee Stuesser
• Profession: Justice of the Ontario Court of Justice - Professor of Law, Bond University
• Pages: 206-209

Page 206

Expert evidence will be treated as "novel science" where there is no established practice among courts of admitting evidence of that kind, or where the expert is using an established scientific theory or technique for a new purpose. In order to be admissible, "novel science" must:

· be essential in the sense that the trier of fact will be unable to come to a satisfactory conclusion without the assistance of the expert;

· be subjected to special scrutiny with respect to its reliability; and

· satisfy an even stricter application of the "necessity" and "reliability" inquiries where the expert opinion approaches an ultimate issue in the case.

Even where there is an established practice of admitting a kind of expert evidence, if the underlying scientific theory or technique is challenged and that challenge is realistic either because that theory

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or technique has not previously been closely scrutinized, or because of changes in the base of knowledge, the expert evidence should not be admitted without confirming the validity of the underlying assumptions.

The "dramatic growth in the frequency with which [expert witnesses] have been called upon in recent years . . . led to an ongoing debate about suitable controls on their participation, precautions to exclude junk science, and the need to preserve and protect the role of the trier of fact."¹⁴³As a result, courts have developed safeguards that apply where scientific theories or techniques may realistically be unreliable. Where areas of expert testimony are well established and familiar, there is generally little need to be concerned about this. Where the "science" is not established, however, there is an increased risk that "expert" witnesses will be presenting worthless or misleading information to triers of fact who may be unable to identify it as such and who will defer to the "expert" because of the expert’s credentials. Where the science or theory is "novel," three particular requirements are therefore imposed:

· although the "necessity" requirement is not to be applied too strictly for established science, with respect to "novel science" the opinion evidence must be "essential in the sense that the trier of fact will be unable to come to a satisfactory conclusion without the assistance of the expert";¹⁴⁴· there must be a "special scrutiny" of reliability undertaken;¹⁴⁵and

· "the closer the evidence [about a novel scientific technique] approaches an opinion on an ultimate issue, the stricter the application . . . ."¹⁴⁶Where the evidence relates directly to the ultimate issue, "very careful scrutiny" is required.¹⁴⁷Exactly when this more intense examination will be called for is not entirely settled because "novel science" has not been authoritatively...