Richard David Barker, 28, who was committed to the Alberta Hospital in Edmonton, is on the run from police. ((Edmonton Police Service))

A Calgary man who made headlines with two robberies and nine carjacking attempts in 10 hours last year is on the run from police.

Richard David Barker, 28, was on a field trip from Edmonton's Alberta Hospital, where he was committed last year, when he jumped into a van belonging to Capital Health and drove away, said police on Wednesday.

Officials warned that Barker should not be approached as he may become violent, even if unprovoked.

Barker was arrested in May 2008 after a string of carjackings and robberies with a handgun in a span of 10 hours in Calgary.

In one of the incidents, Barker stole a van from a woman and drove away with her nine-year-old daughter still inside. A 75-year-old man was also assaulted during the crime spree.

Barker was found not criminally responsible because of a mental disorder in November, and placed at the Alberta Hospital.

A psychiatrist testified at his trial that Barker thought he was the son of God and was hearing voices.

Barker was on a field trip with several other individuals at the Alberta Railway Museum in northeast Edmonton on Monday morning when he fled in the van.

The unlocked van, with the keys found inside, was recovered in Calgary on Tuesday. Police said there's a possibility Barker is on his way to Vancouver.

Barker, last seen wearing a maroon shirt and dark-coloured sweatpants, is now wanted on a Canada-wide warrant for escaping lawful custody.

He's described as five feet, eight inches, 155 pounds with blue eyes and blonde hair. Barker has a 2.5-centimetre scar on his chin and a Grim Reaper tattoo on his right upper arm.