MANDEL: DNA links gun to accused cop killer, court hears

Article content

Glock 19 was used to knock down OPP CONST. Greg Pierzchala’s DNA profile is linked to Randall McKenzie, one of two people currently on trial for first-degree murder.

Article content

Forensic scientist Renata Dziak testified that the grip and slide swab of Glock 19 recovered from the murder had a mixture of DNA profiles of four people, which was 620 billion times more likely to be derived from Randall McKenzie, while the four unknown people who were not associated with McKenzie originated from Randall McKenzie and three unknown people.

Glock’s magazine’s swab will be loaded, showing Mackenzie is the main DNA profile, with odds exceeding him.

Dziak said the co-defendant of Mackenzie’s then friend Brandi Stewart-Sperry, had no trace of DNA on the gun.

McKenzie 27 and Stewart-Sperry, 32, pleaded not guilty to first-degree murder in their Cayuga trial.

Article content

On December 27, 2022, the 28-year-old OPP rookie had just passed the probation that morning, responding to reports of a car in a ditch west of Haggsville near Brantford. This is just a normal phone call.

Pierzchala arrived on the Indian route and found a running Nissan fleet with several people nearby.

The forensic scientist said the DNA profile obtained from the swab of Nissan’s steering wheel shows that Stewart-Sperry cannot be ruled out as the source—in fact, the possibility that DNA originated from her DNA compared to some unknown women is higher.

Article content

The gray track pants caught in Nissan’s front passenger seat bleed on the cuffs, DNA analysis found that the result was trillions of times more likely to come from Mackenzie than those who had nothing to do with him. Dziak said.

The jury heard that Nissan Armada was stolen the day before – but Pierzchala didn’t know that when she stopped investigating.

A young man and woman stand on the side of the road as the officer approaches. Another woman stopped to help. Pierzchala’s body-faced camera captures his own killer as the man in a hooded fluffy jacket suddenly fired six shots through the hoodie’s kangaroo pocket.

The couple then stood out in the Chevy Silverado owned by the Good Samaritan. After a brief pursuit, two suspects attempted to escape from nearby woods and were arrested by OPP later that day.

The main problem of the trial is identification – Mackenzie denied that it was the person in the footage played by Pierczchala.

That’s where OPP forensic video analyst Ronald Schistad came in.

His mission is to compare the image of the killer to McKenzie’s video, which includes selfies on his caught phone, showing him driving while wielding a gun.

Schistad proposed a series of very similar images to compare the two, eventually causing the jury to decide.

The experiment continues.

mandel@postmedia.com

Share this article in your social network