When you cross the border into Canada from the USA, you are subjected to a search, where there is a lower expectation of privacy than you would otherwise have. A recent decision of the Ontario Superior Court considered the use of both detector dogs and ion scanners at the border. The case involved a truck driver crossing into Canada with a load of oranges, and upon inspection they found 30 kilograms of cocaine hidden among the oranges. Subsequently, the detector dog, Pumba, made an indication on a suitcase in the cab of the truck. A search of the bag revealed no drugs, although a swab of the suitcase put through an ion scanner tested positive for cocaine.
While normally detector dogs would be used to provide the human handler with grounds for a search, in this case, the Crown wanted to lead the evidence of Pumba, the detector dog, as proof that at one point the cocaine was in the suitcase. The Court rejected the evidence being led for that purpose, instead limiting the evidence to part of the narrative.
The ion scan of a swab of the suitcase tested positive for cocaine, although no cocaine was visible in the suitcase. The Court considered whether this evidence could be lead. The Court ruled that the results are admissible, although the Court attached very little weight to it and noted that the probative value was limited for a number of reasons: it may yield a false positive, cannot identify when the drug was there, and that there was no evidence that the device underwent regular maintenance checks.
The takeaway from this is that detector dogs making an indication is not, in of itself, evidence that drugs were once stored in a suitcase. While ion scanners provide a more reliable assessment, it is not very probative and will likely be given little weight. These are two tools that provide officers with grounds to search, but on their own are unlikely to be sufficient evidence to establish guilty beyond a reasonable doubt.
Link to case: https://www.canlii.org/en/on/onsc/doc/2018/2018onsc3761/2018onsc3761.html?resultIndex=1