The man who drove a snowplow erratically through Toronto streets one winter morning two years ago appeared "emotionally disturbed," testified a paramedic who saw him the day Sgt. Ryan Russell was killed.

Shannon Willis was one of the paramedics called to the scene on Avenue Road on Jan. 12, 2011, after Russell had been hit by a snowplow.

Shannon Willis testified in court Thursday about the morning of Jan. 12, 2011, when she saw the snowplow that had struck Toronto police Sgt. Ryan Russell just minutes before. (CBC)

Russell, an 11-year police veteran, was later pronounced dead in hospital. The 35-year-old left behind a wife and young son.

Inside a Toronto courtroom on Thursday morning for the trial of Richard Kachkar, Willis told jurors the call for help came in at 6:09 a.m. ET. It was known that an officer was hurt, a snowplow was involved and shots had been fired.

When paramedics left their station at Davenport Road and New Street, they encountered two snowplows.

One snowplow ran a red light. The other, the plow that killed Russell, stopped.

Driver yelled about 'shots fired,' witness says

Willis said the driver behind the wheel of the snowplow that stopped had his door ajar and was yelling.

She testified the driver "yelled something about shots fired, the Taliban and they can all go f--k themselves."

Willis said the driver was full of excitement and adrenaline. She was scared because the driver knew about shots being fired.

When paramedics got to the fallen officer, he was unconscious.

After Russell was brought to hospital that morning, Willis said she sought out the first officer she could find to report the interaction with the driver.

Willis later said in a police interview that she believed the driver was crazy, and not under the influence of drugs or alcohol.

In court, the defence asked Willis if she had formed an opinion about the driver's condition. She said he appeared "emotionally disturbed."

While Willis said she came to her conclusion based on "years of experience," she admitted she had not had any psychiatric training.

Kachkar, 46, has pleaded not guilty to first-degree murder and dangerous driving.

On Thursday, jurors also heard testimony from Sgt. Timothy Irish, the lead forensic investigator in the case.

Irish said the door of Russell’s cruiser was closed when the collision occurred involving the snowplow.

Officers determined that Sgt. Ryan Russell fired three shots before he was hit by a snowplow on Jan. 12, 2011. (Court exhibit)

Jurors have previously heard that Russell was outside his cruiser when he was struck and fatally injured.

Irish showed jurors pictures taken after the incident, including where the shots fired from Russell's gun hit nearby buildings.

Officers confirmed that Russell fired three shots before he was hit by the snowplow.

The trial has adjourned for the week. It will resume on Monday.

With files from the CBC's Steven D’Souza and The Canadian Press