WINNIPEG -- The Winnipeg police officer accused of an alleged assault during an arrest four years ago gave testimony in his trial, telling the court he did use force in the arrest following a high-speed chase.

Patrol Sgt. Sean Cassidy is facing one count of assault causing bodily harm in connection with an arrest in Winnipeg on March 28, 2017.

The charge has not been proven in court. Cassidy has pleaded not guilty.

On Friday, Cassidy took the witness stand for the first time, telling the court he had been returning to his home in La Salle, Man., from his job at the Winnipeg Police Headquarters building in Winnipeg, late at night on March 27, 2017.

Cassidy – a police officer of 24 years – said he had been driving his van home and was still wearing his police uniform and bulletproof vest – though he had a coat over his uniform and had left his belt with his firearm at work.

"As I was about to turn in to my street, I noticed that there was a truck sitting in the shadows by the mailboxes," Cassidy told the court, adding there had been a recent rash of break-ins in La Salle and two trucks had been spotted in connection to one of the break-ins.

"It is suspicious to have a vehicle parked there at this time of night and I wanted to see what they were up to."

Cassidy said he followed the truck, getting its licence plate and running it through the Canadian Police Information Centre (CPIC). He said CPIC later confirmed the truck was registered to an address in Pine Falls, Man.

Cassidy said he phoned 911 to report the suspicious vehicle, but was placed on hold with the RCMP dispatch. The 911 call was played for the court on Friday.

COURT HEARS OF HIGH-SPEED CHASE THROUGH LA SALLE INTO WINNIPEG

Cassidy said he continued to follow the truck from a distance – at one point, he said the driver of the truck stopped, got out and walked up to a house. When he returned, Cassidy said he walked towards his van and swore at him, telling Cassidy to stop following him.

Cassidy said he backed off but continued following – which is when he said the driver of the truck did a sharp U-turn and began to follow him.

Cassidy said he immediately put his van in reverse, spun around and tried to get away.

What followed – Cassidy told the court – was a high-speed chase reaching speeds up to 150 km/h through the streets of La Salle, along Highway 330, and onto the Perimeter Highway.

Cassidy said just past St. Mary's Road, the truck that was following him turned onto a dirt road, looped back and turned north onto St. Mary's Road. Cassidy said he followed.

CASSIDY PUNCHED DRIVER TWICE, USED SHIN PIN, COURT HEARS

In court on Friday, Crown prosecutor Brett Rach submitted video footage of the arrest captured by Winnipeg police helicopter Air1 shortly after 1 a.m. on March 28, 2017.

The video shows a truck driving north on St. Mary's Road, followed by a van. The video shows the truck pass a parking lot where a Winnipeg police cruiser car is sitting, and pull over to the side of the road.

It shows the minivan and police cruiser pull in behind the truck as the driver gets out.

"He jumps out, he jumps into right away an angry and combative stance," Cassidy said, adding he and the two other police officers on scene got out of their vehicles as the driver of the truck got back in his.

Cassidy said he ran up to the driver's door, identified himself as a police officer and ordered the driver to show his hands.

He said he opened the driver's door and struggled to pull the driver from the truck, which is when he saw a metallic object in the driver's hand. Thinking it could be a knife or weapon, Cassidy said he used a Winnipeg police' distraction technique' – a punch to the left side of the driver's face.

He said after the strike, he pulled the driver from the truck and to the ground, but Cassidy said the driver tucked his arms under his body. He said at this point, another officer had come, and together the two attempted to handcuff the driver.

Cassidy said he twice told the driver to "show me your hands," and then used the distraction technique again, punching the driver in the left side of his face.

He said while the other officer handcuffed the driver, he pinned the driver's shoulder to the ground using what he called a shin pin.

Cassidy said he did not strike the driver any other times during the arrest.

The metallic object in the driver's hands was later determined to be a vape pen, Cassidy told the court.

WPS TRAINER WEIGHS IN ON AIR1 FOOTAGE

Rob Tighe, an officer with the Winnipeg Police Service who trains officers on how to conduct high-risk vehicle stops, told the court the Air1 video does not show a textbook stop.

He said officers are trained to have two marked cruisers with four uniformed officers on the scene before initiating the stop, but said that can change depending on a suspect's actions.

"I'm going to suggest to you, looking at the viewpoint, given what you saw, you weren't able to see very well the driver's side of the vehicle," defence counsel Lisa LaBossiere said in her cross-examination of Tighe. "You can't see what exactly the driver was doing or not doing."

"Correct," Tighe said.

Court heard previously that the driver of the truck – Jamie Cote – was released following the arrest without charges.

The trial is set to continue, although no date has been set.