Kemon Edwards was charged with firearm offences.
The Crown sought to admit expert evidence from Detective Scott Ferguson on the characteristics of an armed person based on surveillance video, and from Dr. Robert Gerard on gunshot residue (GSR) found on the accused's clothing.
The court qualified Detective Ferguson as an expert but limited his testimony to general characteristics, prohibiting him from commenting directly on the video's content to avoid usurping the jury's role.
Dr. Gerard's expertise on GSR detection was accepted, but his testimony was restricted from opining on the percentage of particle transfer from an unpublished study, though he could generally comment on the risk of contamination and the significance of particle numbers.
The court emphasized that contamination risks affect the weight of GSR evidence, not its admissibility, and are for the jury to assess.