Thanks to a tip from a 10-year-old girl, a Whitehorse man has been sentenced to 16 months in jail after the RCMP discovered an illicit gun manufacturing operation in his mobile home last summer.

Steven Rathburn, 40, pleaded guilty to possession of stolen property as well as prohibited and restricted weapons, found in his Northland Trailer Park home.

The RCMP raided the home last July 20, finding a small cache of weapons being manufactured on site, "as well as other paraphernalia,” territorial court Judge Peter Chisolm stated in a recent ruling.

"The commercial operation that they had unearthed was significant,” he said.

Police seized two rifles and a nine-millimetre handgun that had previously been reported as stolen.

They confiscated 12 other prohibited and restricted firearms, "a substantial amount of ammunition,” pistol and rifle components, body armour plates, an armoured facemask, silencers, flare suppressors and other weapons parts.

Officers also seized a computer containing designs for weapons and assembly instructions.

Crown prosecutor Terri Nguyen said today a second accused, Dustin Mackie, had been teaching a 10-year-old girl to use some of the illegal rifles.

The girl told an adult who informed police, who in turn questioned the child further about what happened, leading to the summer raid.

"I don't think it's unusual in a territory full of firearms that kids are taught about firearms safety ... but she indicated that she was learning to use handguns, which you don't hunt with,” Nguyen said.

The illicit firearms were assembled mainly in a shed adjacent to Rathburn's trailer.

"Rathburn was not involved in the actual trafficking of these weapons, but did assist in manufacturing them,” the judge said.

Mackie, 41, also lived in the trailer. He appeared to be heading the operation, RCMP deduced.

"It became apparent to the police that this second individual, not Mr. Rathburn, was the principal actor in this illegal endeavour,” Chilsolm said.

Mackie pleaded not guilty to several indictable offences related to the gun operation and stolen weapons.

He appeared in court today to elect whether to proceed via territorial court or Yukon Supreme Court.

On top of a 16-month sentence — with 10 months left to serve due to time spent in pre-sentence custody — Rathburn faces a 10-year firearms and weapons band and 12 months' probation.

He is prohibited from communicating with Mackie and three other people.

"It is unclear how Mr. Rathburn became caught up in this criminal venture,” Chilsolm said.

"It has been noted that the only profit he made was that the principal player, his roommate, continued to pay his rent to Mr. Rathburn, who was the leaseholder of the trailer in which they lived.”

The judge said Rathburn "is described as a quiet, polite and respectful inmate.”

Born and raised in the Yukon, Rathburn had a stable upbringing despite an alcoholic father, the judge stated.

He has a Grade 10 education and no prior criminal record.

Rathburn has a history of mental health issues, including psychotic episodes in 1998 and 2004, leading to a diagnosis of schizophrenia and an anxiety disorder.

He has been unable to maintain employment during the last 10 years, although "under the supervision of various medical professionals, he has done ‘extremely well over an extended period of time,'” Chilsolm said.

"Even though Mr. Rathburn was not the principal actor, the illegal situation in which he participated is a very serious one.

"The introduction of illegal firearms into this community cannot be tolerated.”