It is safe to say that pretty much everyone working in the forensic sciences has heard of the Daubert ruling or, more specifically, Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993).1 It was a pivotal ruling that, together with two subsequent rulings General Electric Co. v Joiner, 522 U.S. 136 (1997)2 and Kumho Tire Co., Ltd. v Carmichael, 526 U.S. 137 (1999),3 has greatly affected many legal jurisdictions in the United States. And, as is often the case, what happens in the USA also tends to have influence elsewhere.
A few years later in Canada there was a key Supreme Court of Canada ruling that addressed admissibility of forensic expertise — R. v. Mohan,  2 S.C.R. 9.4 That is the ruling which laid out the test for the admissibility of ‘novel’ expert evidence (see Mohan, page 4) in Canada. Subsequently, the factors explained in that ruling have been applied, just as those in Daubert were, to many types of traditional forensic science evidence. It is rather ironic that rulings intended to liberalise the admission of new (and potentially) helpful evidence would lead to challenges of all forms and types of evidence.