An undercover RCMP officer feared for his life as a homicide suspect he was targeting suddenly turned on him as they drove away from a Barriere gas station.

Mark Lindsay, who was subsequently charged with the second-degree murder of Dana Turner in Alberta, is also charged in Kamloops with robbery and aggravated assault over the incident in Barriere last fall.

He pleaded not guilty Tuesday to the Kamloops charges as his trial opened in B.C. Supreme Court.

The undercover operation was organized by Edmonton police, who considered Lindsay to be a suspect in Turner's disappearance. Turner was an ex-girlfriend of the suspect. Her body was eventually found last October near Innisfail, Alta.

Last September, Edmonton police concocted a scenario to draw Lindsay into their confidence in hopes of obtaining information on what was then a missing person case, said Crown prosecutor Will Burrows.

The undercover officer, who can be identified only as SM, boarded a Greyhound in Hixon, Alta., knowing the suspect was on board. He befriended Lindsay and they later reconnected in Edmonton with the promise of "work," but there was no discussion of criminal activity, SM told Justice Dev Dley in his testimony on Tuesday.

As they got acquainted, Lindsay asked SM to drive him to an Edmonton hotel so that he could check out the premises. When they arrived, Lindsay wouldn't get out of the vehicle to do so until SM urged him on. Turner's vehicle was later found at the same hotel, SM said.

Lindsay opted out of an initial drive to Saskatchewan but was later persuaded to join SM to deliver a truck and trailer with two ATVS in tow, the court was told.

On Sept. 21, the pair set off to deliver the quads to Kamloops and stopped in Barriere after midnight to pick up snacks, SM said. Lindsay returned to the vehicle and offered SM a chocolate bar.

As they pulled back onto the highway, SM looked over to see Lindsay's teeth clenched and his hand drawn back. Then Lindsay jumped over the console and tried to put him in a headlock, attempting to stab the officer, still harnessed in his seatbelt. The officer fought back and remembered he'd left the window open, so he dove out, head first.

"You could say I was fighting for my life," SM testified.

At that point, an ambulance pulled in on its return to Clearwater. Paramedics could see a scuffle in the truck's cab and radioed to dispatch that there was a "domestic" in progress. SM, bleeding from a laceration above his eye, informed them he was an undercover officer, one of the paramedics testified.

At that point, after a couple of minutes on the side of the road, Lindsay fled southbound on Highway 5. He was intercepted and arrested by police near Vinsulla.

In earlier testimony, Barriere RCMP Const. Evan Cadwallader said a hooked carpet knife, the alleged weapon in the assault, was found in the truck's cab. SM testified he did not see the weapon.

"This was a classic, Psycho movie sort of, fist up in the air, then down towards you?" Don Campbell, defence counsel, asked SM in cross-examination. "I'm going to suggest that, if this was the object with a bright yellow handle and a four-inch blade, you would see it."

No, it was dark, SM replied.

At no time during the operation did Lindsay show any sign that he knew or suspected he was being deceived, SM said.

In addition to the robbery, assault and weapons charges, Lindsay is facing another count of aggravated assault stemming from a fight with an inmate while he was in custody at KRCC. Lindsay is alleged to have stabbed another inmate in the eye with a pencil.

The Kamloops trial on all four counts continues today.

A preliminary hearing in the Turner murder case is set for Jan. 8, 2013, in Red Deer, Alta. Lindsay - the adopted son of a former chief of police in that city - is also charged with causing an indignity to a body and obstruction of justice in that case.

myouds@kamloopsnews.ca