The man behind one of Canada's most notorious killings says he is sorry for beheading and eating parts of a Winnipeg man on a Greyhound bus in 2008, but says his schizophrenia lead him to believe he was attacking an alien.

Vince Li became known around the world as the man who dismembered and cannibalized fellow bus passenger, Tim McLean.

Li was found not criminally responsible for the killing in 2008, and was committed to the secure wing of the Selkirk Mental Health Centre in Manitoba.

Recently, Li made headlines when a review board granted him permission to leave the hospital premises for short escorted trips into the neighbouring town of Selkirk

The ruling sparked outrage from members of the public, including the victim's mother.

In response to the outcry, authorities at the Manitoba Schizophrenia Society decided to conduct an interview with Li and release the transcript to the public.

Chris Summerville, director of the Manitoba Schizophrenia Society, says he decided to conduct an interview with Li because he feels the 44-year-old has not been fairly treated by the media or the public.

Summerville believes Li is making progress and hopes this interview might shed light on his improvement.

"(Li feels) remorse, a degree of humility -- I know a lot of people won't believe that -- regret and a sense of torment," Summerville said.

"He understands now that schizophrenia is a mental illness which plays tricks on the brain. He knows that the medication works to keep the voices away."

The edited transcript, which was released to the media Tuesday, contains a description by Li of what happened on the bus on July 30, 2008-- the night he killed the 22-year-old McLean.

According to the transcript, Li believed McLean was an alien who needed to be destroyed. Li also thought God was instructing him to kill McLean in order to protect others.

In the transcript, Li talks about buying a knife to protect himself from aliens, as well as hearing voices telling him to cut off McLean's head -- something Li now recognizes was wrong.

"I remember cutting off his head. I believed he was an alien. The voices told me to kill him, that he would kill me or others," says Li in the transcripts. "I do not believe this now, it was totally wrong. It was my fault. I sinned, but it was the schizophrenia."

According to the transcript, Li understands that people fear him, but he wants people to know that he no longer hears voices and is no longer a risk.

"I understand people are scared because of my behaviour on the Greyhound bus. I am not at risk for anybody. I don't believe in aliens. I don't hear voices," the transcript reports Li as saying.

Summerville -- who believes Li is also a victim -- says the man also wants forgiveness for his actions.

"I would do anything for (McLean's) family. I would ask forgiveness, but I know it would be hard to accept," the transcript reports Li as saying.

But forgiveness does not seem possible for the victim's mother, Carol Dedelley.

Dedelley is unconvinced that Li no longer poses a threat to society and says no apology can replace the loss of her son.

"Mentally ill killers that are this unpredictable and dangerous -- I think they have to stay (in custody) forever," said Dedelley.

With file from CTV's Jill Macyshon and The Canadian Press