01/17/2014 11:40 EST | Updated 03/19/2014 05:59 EDT

Oil patch worker who concealed gun from police convicted

A noise complaint has embroiled an oil worker in a lengthy legal battle that ended today before the Supreme Court of Canada.

Erin Lee MacDonald was convicted of several weapons offences after police came to the door of his downtown Halifax condominium in December 2009.

Police were there to ask MacDonald to turn down his music. When he answered the door, one of the officers noticed him concealing something "black and shiny" in his right hand.

According to police testimony, MacDonald failed to answer questions about what he had in his hand, so police kicked in the door. There was a struggle and police discovered MacDonald was holding a loaded 9-mm Beretta handgun, a restricted weapon.

Macdonald divided his time between Calgary and Halifax and was licensed to carry the gun in Alberta.

At his trial, MacDonald was convicted of careless handling of a firearm, possession of a weapon for a purpose dangerous to the public peace and possession without authorization of a loaded restricted firearm. He was sentenced to three years in prison.

MacDonald appealed his convictions.

He argued — in part — that his charter right against unreasonable search and seizure was violated when police kicked open his front door.

MacDonald also claimed he shouldn't be convicted for illegal possession because he didn't realize his Alberta permit wasn't valid in Nova Scotia.  

The Nova Scotia Court of Appeal agreed with some of MacDonald's arguments. The court reduced his sentence, and acquitted him on the weapons possession charge.

In its ruling released today, the Supreme Court of Canada said police did not violate MacDonald's rights.

"The officer had reasonable grounds to believe that there was an imminent threat to public and police safety and that the search was necessary to eliminate that threat,” read the court ruling.

The court went on to say, "MacDonald's subjective belief that he could possess the firearm in his Halifax home is a mistake of law and that mistake is no defence."

The Supreme Court has referred the matter back to the Court of Appeal for sentencing.