A former leader of a Scouts Canada troop has received a conditional community sentence for shooting a 12-year-old scout four times with an airsoft gun in Calgary.

Todd Robertson, who is 49, had pleaded guilty to an assault with a weapon charge.

Court documents say he shot the boy during a fundraising and firearms event in Calgary last year after becoming very frustrated with the boy's behaviour.

On the last night of the trip Robertson lost his temper when a group of scouts shot a clay pigeon and were making too much noise.

Robertson then picked up an airsoft rifle and fired at the boy from a range of about four metres, hitting him with pea-sized plastic pellets in the face, both arms and on the knuckle of his right hand.

15-year volunteer

Provincial court Judge Allan Fradsham sentenced Robertson to six months to be served in the community.

Fradsham noted the shooting took place a month after Robertson received an award from Scouts Canada for good service.

"He volunteered with Scouts Canada for 15 years," Fradsham said in his written judgment. "As Mr. Robertson said when he addressed the court, and I accept, he went into scouting 'to help' individuals."

Fradsham said after Robertson fired at the boy he shot his own hand with the gun and didn't realize the pellets would be so painful.

Expelled from Scouts Canada

Robertson must also take an anger management course, not possess any weapons, not consume alcohol and remain at home when not working, shopping or attending medical appointments.

He must also provide a DNA sample and is banned from owning firearms, bows and explosives for 10 years.

The boy, who can't be named due to a publication ban, suffered two scars from the pellets.

Court records say Scouts Canada "expelled" Robertson from the organization immediately after the July 2016 shooting.