Mark Lindsay yelled "You're casting black magic on me" before twice stabbing his cellmate in the eye during a "psychotic episode" at Kamloops Regional Correctional Centre in October 2011, his alleged victim testified in B.C. Supreme Court in Kamloops Tuesday.

Lindsay, the 25-year-old son of former Edmonton police chief John Lindsay, is on trial for aggravated assault against his former cellmate, 22-year-old Michel Fougere.

"I know for a fact he was trying to kill me," Fougere testified.

At the time, Lindsay had been awaiting trial for charges of aggravated assault against a police officer.

(He was tried for the charges last week and Crown has requested a psychiatric evaluation, which the judge supported, setting a deadline for its conclusion of Sept. 4.)

Fougere shared his cell at KRCC for nearly two weeks while in remand for breaching bail conditions on robbery charges.

Fougere said there had been no indication of anger or tension during that time, and he had no idea of allegations that Lindsay had attacked an undercover police officer and killed his ex-girlfriend Dana Turner.

Lindsay said one day after sharing his cell with Fougere, he was afraid for his life because Fougere was "subliminally" threatening to kill him.

Lindsay said Fougere was part of the same group of serial killers as Turner, who he admitted in court last week to killing in self-defence.

He said the killers had once surreptitiously left a "classic good guy-bad guy" superhero comic book in his apartment. That made it clear to him that they saw themselves as vigilantes targeting him as a "low life" for a rape Lindsay denies committing.

He said after killing Turner, the threats he received through phone calls and in radio broadcasts eased up.

"Getting rid of someone threatening my life made me feel better," he said from the prisoner's box while clad in a red jumper, socks and shackled hands and feet.

But that sense of safety didn't last and when he was approached on a bus trip from Vancouver to Edmonton by what turned out to be an undercover police officer investigating Turner's death, he once again felt threatened and he attacked.

That landed him in KRCC with Fougere.

Lindsay testified that he heard Fougere threaten to kill him numerous times. He said Fougere said: "If that's why you killed Dana, you want to kill me, too."

He said he'd come to the point of panic because Fougere had cast a black magic spell on him. He continued to try to befriend Fougere, thinking he wouldn't want to kill him if he got to know him.

"All three times it didn't turn out so well," said Lindsay referring to his attempts to befriend Turner and the undercover police officer. "Maybe I just should have run. It just shows how serious that situation was."

On October 20, 2011, the jail was on lockdown to accommodate a temporary staff shortage while prison guards had gone to lunch, according to testimony from KRCC guard William Chin, whose job was to roam two cell blocks while other staff were on break.

Fougere said he and Lindsay were on opposite sides of the bottom bunk playing Scrabble when, without a hint of warning, Lindsay yelled "You're casting black magic on me," grabbed the back of Fougere's head and stabbed him in the left eye with a pencil.

The men fought while Fougere tried to reach the emergency call button. Lindsay said he believed pressing the button would bring Fougere's father to help him kill Lindsay.

Fougere was able to reach the button then fell to the floor.

Lindsay then became subdued.

"I held his hand and said 'You know why I had to do this,' and he nodded," testified Lindsay. "That told me he wasn't just a normal person."

Once on the floor, Lindsay started to cry.

"I was friends with him," testified Lindsay. "I was crying out of sorrow that it had come to that point. I was struggling with it. It was such an alarming attack."

Chin testified that just before he arrived to the cell less than a minute after the call button was pushed, he heard a voice say "Tell the officer you fell off the bunk."

When he entered, he said Lindsay was calm, which he called abnormal.

"Usually if there's an altercation, inmates would be swearing at each other," said Chin.

Lindsay was taken away without incident before paramedics arrived to take Fougere to hospital. He was eventually airlifted to Vancouver for surgery but doctors were unable to save his eye. He is permanently blind in his left eye and suffers pain and migraines, he said.

Fougere's stepfather and mother travelled from Kelowna with Fougere to be at the trial Tuesday. Enrico Cavina said his stepson's injuries have prevented him from finding work.

He said after reading about Lindsay's courtroom admission last week, he feels Lindsay should be kept away from society.

"I don't think society will be safe with him out," said Cavina. "I think such a person shouldn't be walking on the streets."

The trial resumes Wednesday when the Crown takes over questioning Lindsay.