Jury members at the trial of two people, accused of killing an Ontario Provincial Police officer, were shown DNA and video evidence Thursday at a Cayuga, Ont. courthouse.
Randall McKenzie and Brandi Stewart-Sperry are both charged with the first-degree murder of Const. Greg Pierzchala. He was shot six times on Dec. 27, 2022, while responding to a report of a vehicle in the ditch along Indian Line, near Hagersville, Ont.
Renata Dziak from Ontario’s Centre of Forensic Sciences, testified about DNA testing on items seized during the police investigation. She compared DNA found on the items to samples collected from a number of people, including McKenzie and Stewart-Sperry, as well as police officers involved in the case.
One of those items was a Glock 19 that was found after McKenzie’s arrest.
Dziak said a swab was taken from the slide and grip of the gun and the DNA of four people was identified.
She testified that McKenzie cannot be excluded as a contributor, and it is 620 billion times more likely that the DNA originates from McKenzie and three unknown people than from four unknown people unrelated to McKenzie.
The police officer who seized the gun after McKenzie’s arrest also could not be ruled out as one of the sources of the other DNA.
The forensics expert also said Stewart-Sperry’s DNA was not on the Glock 19.
Dziak also swabbed the gun’s magazine, specifically the area where the bullets would have been loaded. There she identified two sets of DNA.
The witness testified that McKenzie could not be excluded as a major contributor of that DNA. She added that it was a trillion times more likely to be his than any other unknown person.
The jury also heard from Ron Schistad, the digital video analyst with Ontario Provincial Police who was tasked with comparing images of the shooter from Pierzchala’s body-worn camera with photos of McKenzie.
The jury was also shown them side-by-side.
Schistad did not make any conclusions about the comparisons.
During cross examination, McKenzie’s lawyer questioned the quality of Pierzchala’s footage. Schistad said fine detail was lost as a result of the recording and file compression process.
The trial, which started almost three weeks ago, will resume on Friday.
