Calvin Nimoh admits killing a perfect stranger who was out for an evening walk in downtown Toronto, stabbing him nine times in the back, head face and neck.

The lethal injury to cancer researcher Mark Ernsting, 39, was a stab wound so forceful it broke the knife handle from the blade, which remained lodged in his head.

Nimoh, 23, was even willing to plead guilty to manslaughter in Ernsting’s death on Dec. 15, 2015, his trial in Ontario Superior Court heard Tuesday.

But the Crown believes Nimoh is guilty of first-degree murder, and prosecutor Michael Cantlon outlined for a jury the evidence he plans to use in making its case.

It includes the testimony of Glynis Brownsey, a Victoria-based opera and theatre director. She was mugged by two masked assailants, one alleged to be Nimoh, as she walked through a park to a friend’s home in the Summerhill Ave. and Yonge St. area about 90 minutes before Ernsting was attacked.

“The evidence called will present two distinct yet both similarly vulnerable members of this community walking after dark. Actions speak louder than words,” Cantlon told jurors in his opening address.

The Crown also plans to call a young woman who can’t be identified under the Young Offenders Act. She will admit to participating in the robbery of Brownsey, and who will testify Nimoh told her after he believed he had killed the woman in the park, and confessed to killing Ernsting, Cantlon said.

Police arrested Nimoh, then 22, later that night after an anonymous tipster reported two women at a YWCA shelter may have been involved in a robbery. Nimoh was arrested nearby and found with a red handle of a knife — without a blade — and a matching protective sheath on which police detected blood. He was charged with the robbery of Brownsey and then the murder of Ernsting.

Cantlon said jurors must determine whether Nimoh had criminal intent when he fatally stabbed Ernsting, who was walking along McGill St., just east of Yonge St. and north of Gerrard St. He offered no possible motive, telling jurors “the issue for you to determine in this case is why.”

Ernsting frequently went for an evening walk in their downtown neighbourhood before going to bed, always between 9:30 and 10 p.m., his husband Robert Iseman testified Tuesday, smiling briefly through tears at the memory of his partner’s bedtime routine.

The jury heard Ernsting stood five foot nine and weighed 130 pounds. He had a Ph.D and was employed as a biochemical engineer at the MARS facility and at the Ontario Institute of Cancer Research on Carleton St.

Brownsey, who uses her maiden name Leyshon, also took the stand Tuesday.

About 90 minutes before Ernsting was killed, Brownsey was robbed of her purse, stabbed four times, knocked to the ground, punched and kicked. She was 65 at the time.

Brownsey testified that while her theatre training has taught her to be observant, she was unable to get a good look at her two masked assailants.

But she had no trouble recalling her emotional state as she lay on the ground.

Loading... Loading... Loading... Loading... Loading... Loading...

“I was stunned, I was relieved. I was mostly, I remembered, just trying to process what had happened. It was so out of any context in my entire life,” she testified calmly.

The trial continues in front of Superior Court Justice David McCombs.