During a criminal trial for importing cocaine and possession for the purpose of trafficking, a voir dire was held to determine the admissibility of evidence from a detector dog and an ion scan machine.
The accused, a commercial truck driver, was found with 30 kilograms of cocaine in his trailer at a border crossing.
The Crown sought to introduce evidence that a detector dog indicated the presence of a target odour on a suitcase in the truck's cab, and that an ion scan of the suitcase tested positive for cocaine residue.
The court applied the Mohan criteria and held that the detector dog evidence was admissible only for the limited purpose of narrative to explain why the ion scan was conducted, due to its prejudicial effect outweighing its probative value.
The court further held that the ion scan evidence was admissible but would be given very little weight due to the possibility of false positives and its inability to determine when or how the residue was deposited.
