A Glock 19 and gunshot residue were the focus of testimony as expert witnesses took the stand Friday at the trial of two people accused of killing Ontario Provincial Police Const. Greg Pierzchala.
The 28-year-old was fatally shot while responding to a call about a vehicle in a ditch near Hagersville, Ont. on Dec. 27, 2022.
Randall McKenzie and Brandi Stewart-Sperry are both charged with first degree murder in his death.
Gunshot residue testing
Three expert witnesses testified for the Crown on Friday, as the trial wrapped up its third week.
Benjamin Lee, from the Centre of Forensic Sciences, spoke about gunshot residue testing done on various items related to the investigation. He explained gunshot residue on a person can either indicate they discharged a firearm, or that gunshot residue was somehow transferred onto them.
Lee said gunshot residue particles are lost within two to four hours after a gun is fired.
He also noted studies have shown someone can shoot a gun without getting gunshot residue on their hands.
In the Pierzchala investigation, Lee said gunshot residue was found in the stolen Silverado, which was used as a getaway truck. One particle was located near the front of the driver’s seat, and another was behind the driver’s seat.
Two blankets in the vehicle also tested positive for gunshot residue.
Lee said no gunshot residue was found in the samples taken from the hands and face of Randall McKenzie, or the samples taken from the hands and face of Brandi Stewart-Sperry.
As for the black Adidas hoodie seized from McKenzie after the shooting, 14 particles of gunshot residue was found on the outside. The interior of the kangaroo-style pocket on the front was also tested; it had 13 particles of gunshot residue.
One particle of gunshot residue was also found on a black Pajar jacket, found in the area where Randall McKenzie was arrested.
During cross-examination, McKenzie’s lawyer Douglas Holt asked about studies that showed gunshot residue can be found on police, and their equipment or vehicles, ostensibly because they carry firearms.
Lee confirmed he cannot rule out the possibility that the gunshot residue was transferred from some other primary source.
Firearm testing
Next to testify was Jennifer Plath, a certified firearms expert from the Centre for Forensic Sciences.
She tested a number of bullets, bullet cartridges and projectile fragments found during the investigation.
Plath concluded that, within the limits of practical certainty, a fired cartridge case from the shooting scene, and another found in the area where Randall McKenzie was arrested, were both fired by the Glock 19 seized by police.
The jury heard the Glock 19, which is a prohibited firearm in Canada, was legally sold by a firearms dealer in Glendale, Arizona in June 2022. At some point it was illegally trafficked into Canada.
More firearms testimony
The final witness to take the stand was Sgt. Peter Reintjes, a firearms expert.
He examined the Glock 19 and was tasked with comparing it to an image of a gun, and video of McKenzie driving while holding a gun, which were both found on McKenzie’s phone.
The jury was shown photos with details highlighted, but Reintjes did not provide analysis as to what the photos might mean.
Reintjes noted the Glock 19 had an aftermarket covert carry clip added to it, designed so the gun could be hidden inside a waistband.
During cross-examination, McKenzie’s lawyer asked about the popularity of the Glock 19 in the U.S. Reintjes said it is probably the most commonly sold gun.
The trial is scheduled to resume on Tuesday.
