The mental health of a man facing charges in the 2011 death of a Toronto police officer took centre stage Monday morning as his trial got underway.

Richard Kachkar was brought into the University Ave. courtroom in handcuffs, and rarely looked up during proceedings, instead staring at the floor.

Kachkar has pleaded not guilty to one count of first-degree murder and one count of dangerous driving in the death of Sgt. Ryan Russell.

Russell died after he was struck by a stolen snowplow during a police chase in the early morning hours of Jan. 12, 2011.

Superior Court Justice Ian MacDonnell told the jury that the trial isn’t to determine who killed Russell, as there is no dispute that Kachkar was driving the snowplow that killed the 35-year-old police sergeant.

The main issue in the case is Kachkar’s mental state as he drove the snowplow that January day.

Surrounded by family and friends, Russell’s widow Christine sat in court, while Toronto police officers stood outside the courthouse waiting to testify.

Speaking to reporters later outside the courthouse, an emotional Christine Russell said “the healing is stopping and the pain is back.”

She also expressed appreciation for the support shown to her family.

“It’s not easy to sit there and sit so close to someone you know has done so much harm,” she said.

Christine also asked that the media be mindful of how they report the trial proceedings as she must explain it to her son, now 4.

“I don’t want it to hurt him in any way so please be cognizant of that,” she said.

According to the Toronto Police Association, Russell was the first Toronto officer to die in the line of duty since 1994.

The trial continues Monday afternoon.

With a report from CTV Toronto’s Colin D’Mello and with files from The Canadian Press