An Abbotsford police officer described using his cruiser to hit a car he believed was a suspect vehicle following the fatal shooting of a fellow officer in 2017.

The testimony came during the ongoing trial of Oscar Arfmann, 67, accused of first degree murder in the death of Abbotsford Constable John Davidson.

Arfmann has pleaded not guilty.

Constable Shawn Alton told the court he ended up purposefully hitting a black car, that he believed was the suspect vehicle, with his own cruiser.

Alton testified he also heard "several shots being fired" but wasn't sure where the noises were coming from and that the driver of the car "appeared to be stunned" and was moving his hands up and down.

He told the court he could see the stock of a rifle inside the car.

Alton testified at this point, other officers were arriving and giving the man in the car commands, mostly to keep his hands where they could see them.

"It was chaos," Alton testified.

He told the court police initially tried to see if a canine unit could pull the driver from the vehicle, but it didn't work.

He also testified that the suspect was eventually taken out of the vehicle through the driver's side.

"He was covered in blood," Alton said, telling the court the man had a large gash on the top of his head.

Alton testified he seized a wallet, passport, and bullets from the man, along with two or three folding knives.

Under cross examination by the defence, Alton agreed he did not actually see the car leaving the parking lot of the shopping complex on Mount Lehman Road where Davidson was shot on Nov. 6, 2017.

Alton testified he was sure he was intercepting the right vehicle, calling it a "moment of clarity."

"This was the person that had just committed this violent crime," Alton testified. "There was no guesswork in that."

Last week, the court viewed dash cam video from a witness who testified he believed he was following a man with a gun.

Lawrence Siefert told the court he was in a McDonald's drive-thru at the shopping complex when he heard two loud bangs.

Two loud noises could also be heard when the court viewed dash cam video from Siefert's truck.

Siefert testified he then saw "a guy standing in front of me with a rifle". He told the court the man was standing between a blue pickup and another vehicle. He testified the man appeared to be trying to reload the rifle.

The dash cam video showed a brief glimpse of someone standing between two vehicles holding something as Siefert's truck turns.

Siefert can then be heard on the video calling 911 while driving around, telling the call taker there's someone "shooting up cars."

During the call, Siefert describes the man's vehicle either a black Mustang or Camaro, with Alberta licence plates. He also describes the man to the call taker as having long hair and wearing glasses and a leather jacket.

Siefert testified he followed the vehicle after it left the parking lot. The dash cam video shows him driving behind a car while still speaking to the 911 call taker, who at one point asks him to stop following the car. Siefert testified the car in front of him was driving "casually".

Siefert testified he followed the car back to the parking lot. On the video, sirens can be heard and a marked police car can be seen arriving. The video comes to an end not long after that.

During cross examination, the defence questioned Siefert's memory of what he saw that day.

He agreed he had not actually seen anyone shooting.

At points, Siefert testified he was adamant about identifying the same car.

"I saw the same man standing beside the same black car with the same rifle."

The court also previously heard testimony from a car dealership employee and general manager, who told the court they had recognized a Mustang that had been stolen from their lot days before the shooting, and police were called.

The employee, Corey Thomas, testified he drove his blue Ford F-150 to the shopping complex and boxed in the Mustang so it could not move. He then testified he was confronted by Arfmann.

"He told me to 'move that piece of s***,'" Thomas told the court.

Thomas said he then told Arfmann that police were on their way.

"I'll show you what I have in store for the police," Arfmann said according to Thomas' testimony.

In their opening statement, the Crown said Davidson was the first officer to arrive on scene and was shot twice from behind.