Military training can become 'automatic' response under stress, expert says during Peter Khill trial

Jurors in the Peter Khill murder trial heard a forensic psychiatrist testify Monday that military training can become someone's "automatic" response in a stressful situation.

The defence called Peter Ian Collins to the stand as an expert witness during Day 10 of the second-degree murder trial.

Khill is on trial after shooting and killing Jon Styres in February 2016 when Styres was trying to steal his truck.

Khill, a former reservist, has pleaded not guilty, saying he thought Styres had pointed a gun at him.

In reality, Styres had a knife in his pocket but no gun.

The jury previously heard Khill told the officer who arrested him he was a soldier doing as he was trained.

They also heard Khill's superior officer in the 56 Field Regiment in Brantford, Ont., testify reservists are taught "to be ready to kill if needed."

Stressful events can impact memory: expert witness

Collins said Monday if someone had several years of training as a reservist, the training could impact their response to a stressful situation, even if that situation happened years after their training.

"With some individuals, the skills become … in a sense, automatic," he said.

Collins added high-stress situations can impact people's perception, citing a study where over half of 157 officers who experienced an officer-involved shooting experienced gaps in the memory.

Some of their memories were distorted, he said.

Collins added it can also affect their perception, affecting what someone sees, hears and more.

"Time can slow down, time can speed up … things can be magnified," he said.

"When people are under stress, they may perceive things that actually didn't happen and recall things that didn't happen."

Collins also said when someone is in a dangerous environment, they may overestimate the amount of danger in a situation in order to avoid missing any danger.

Training 'doesn't turn you into a robot': prosecutor

Crown prosecutor Paul McDermott cross-examined Collins, having the expert acknowledge just because someone has had years of training doesn't mean they can't make another decision.

"Whatever training you have, you can just ignore it in any given situation," McDermott said to Collins.

"But the problem with this type of training and why its repetitive is that it becomes so engrained it becomes intuitive that this is what they're going to draw upon most of the time," Collins responded.

"But they have the ability to ignore it ... it doesn't turn you into a robot or automaton," McDermott said, to which Collins agreed.

McDermott also had Collins acknowledge that military training could improve decision making.

"It makes you potentially calmer and more able to make an assessment in a dangerous situation than someone who didn't have that training," McDermott said to Collins.

"Yes," Collins replied.

Closing arguments are expected to start Wednesday and the 12-person jury is expected to start deliberating Thursday.

Justice Andrew Goodman dismissed a juror because they became ill and Goodman didn't want to delay the trial.