It was Halloween, but a prolific offender wasn’t in costume when he was spotted carrying a shotgun by a passing motorist.

Ray Simpson pleaded guilty Wednesday to charges of carrying a concealed weapon, possession of heroin and breaching court-ordered firearm and narcotics bans.

The plea to the charges came after several hours of trial. Defence lawyer Sheldon Tate said his client wanted to change his plea.

Simpson is set to be sentenced Thursday. The defence was expected to argue that police didn’t have reasonable and probable grounds to arrest Simpson.

A passing motorist spotted a man on Halloween last year clutching a partially hidden rifle or shotgun against his body. He had just hopped out of a black pickup in the parking lot of a residential building in the 1700-block of Tranquille Road and walked past her on the sidewalk.

He was seen again minutes later by another man, who testified he thought Simpson was holding an umbrella.

The woman who first spotted the man carrying the gun called RCMP, who were close by and arrived in a minute or so.

Testifying as a Crown witness, RCMP Const. Dustin Paquette brought with him a shotgun into B.C. provincial court.

Paquette said he and his partner had found the gun propped up against a wall of the apartment building, with a jacket wrapped around it in an attempt to hide it.

“He said it was there when he got there,” Paquette said.

But Simpson’s guilty plea came amid Paquette’s testimony.

Paquette said Simpson, someone he knew as a prolific offender, was “aggressive, irate (and) panicked” before police arrested him.