By Derrick Blakley

(CBS) — Good cop just doing his job or a rogue police officer responsible for the death of a 95-year-old man? The question will be answered in a Markham courtroom.

That police officer repeatedly shot John Wrana with beanbags, during a confrontation at a nursing home.

Wrana died, but the defense argues it was not from injuries sustained at the home.

CBS 2’s Derrick Blakley reports that testimony on Wednesday was dominated by the prosecution’s star witness, an expert on police use of force who told the court officer Craig Taylor’s actions were unreasonable, unnecessary and reckless.

Frank Murphy is a former New Jersey street cop and secret service agent and now an expert on police tactics.

He testified that even while delusional and wielding a knife, 95-year-old John Wrana was a danger to no one inside his room at the Victory Center Retirement home.

“There was no threat until officer Craig Taylor and the others confronted him,” Murphy said.

From no more than eight feet away, Taylor shot Wrana four times with bean bag rounds from a 12-gauge shotgun, rounds travelling at 190 miles-an-hour.

Murphy said there were other ways to disable Wrana, including using the 30-pound ballistic shield police brought with them.

“Police officers had more than the ability using their shield not only to enter but to knock Wrana down,” Murphy said.

But Taylor’s attorney Terry Ekl dismissed that conclusion.

“Can you imagine if police had bull-rushed this man, knocked him to the ground, broke his neck, given him a concussion?” said Ekl. “That’s the uncontrolled use of force. That’s the last thing they would want to do.”

During cross examination, Ekl got Frank Murphy to admit Taylor’s ballistic vest provided no protection from potential knife wounds and, while Taylor’s actions led to Wrana’s death, Ekl argues, they didn’t have to.

“He went to the hospital. He would have lived, survived, if he agreed to surgery,” Ekl said. “He refused to get it and said I want to die.”

The States Attorney’s office is paying Frank Murphy a $350 an hour consultant’s fee for his expertise. Through November, he’d already charged the county more than $6,000.