Matthew de Grood appeals Alberta Review Board decision to keep him in custody

A lawyer for a mentally ill man who fatally stabbed five young people at a Calgary house party is appealing a determination that he remains "a significant risk to public safety" and wants him released from custody.

Matthew de Grood, 31, was found not criminally responsible for the 2014 killings of Zackariah Rathwell, Jordan Segura, Kaitlin Perras, Josh Hunter and Lawrence Hong because he was suffering from schizophrenia at the time.

He appeared at his annual review hearing last month in Edmonton that assessed his treatment and whether he should be allowed any increased privileges or freedoms over the next year.

The Alberta Review Board ruled that de Grood must remain detained at Alberta Hospital Edmonton or the Southern Alberta Forensic Psychiatry Centre in Calgary, despite a decision a year ago that he was to transition to a group home.

In a notice of appeal released late Tuesday, de Grood's lawyer asked the Alberta Court of Appeal to set aside the review board's order and substitute it with an absolute or conditional discharge.

The notice contends the board's ruling was unreasonable and should be set aside due to procedural unfairness and a reasonable apprehension of bias on the part of the chair.

"The Review Board ignored and/or misapprehended key evidence, and made findings absent supporting evidence, when it concluded the appellant is currently a significant threat to public safety," reads the notice signed by lawyer Jacqueline Petrie.

The notice also contends the review board misunderstood and failed to correctly apply the legal and analytic framework for determining "significant threat" as established by the Supreme Court of Canada.

The board did rule that de Grood can ask for unsupervised passes to both Calgary and Edmonton as well as supervised visits for up to two weeks to visit his sister in British Columbia.

Family members of de Grood's victims have opposed his release or any new freedoms being granted.

Petrie did not immediately respond to a request for comment.

De Grood's trial heard he attacked the individuals at a party, held to mark the end of the school year, believing the devil was talking to him and a war was about to begin that signalled the end of the world.

He told officers he knew what he did was "atrocious" but he was killing Medusas and werewolves.