On Thursday a man who beheaded a fellow passenger on a Greyhound bus in Manitoba has been found not criminally responsible due to mental illness.

Vincent Li was charged with second-degree murder in the death of 22-year-old Tim McLean, but instead of going to prison, he will be treated in a mental institution.

McLean's mother is upset, but not surprised by the decision.

She says the law needs to be changed so that someone can be found not psychologically accountable, but still be criminally responsible for a crime

The group Victims for Change in Alberta agrees.

They are drawing the comparison to Steven Tavares, who was stabbed 28 times by a co-worker in 2004, just outside of Calgary.

His killer was also found not criminally responsible.

Tavares' murderer, Stephan Gaetan Lee, was released less than three years later.

He remains under the Alberta Review Board's authority and is living and working in Edmonton.