A TEENAGE killer who shot a man through the heart with a rifle was today locked up for 17 years.

Jamie Munn, 18, was given a life sentence for murdering 32-year-old Gary Docherty in Duntocher, near Clydebank, last April.

At the High Court in Glasgow, Judge Rita Rae, QC, said: "This was a cold, calculating and pre-meditated killing. You armed yourself with a rifle and went looking for Mr Docherty.

"You did not appear to have a serious motive other than the fact Mr Docherty had had a fight with some of your friends. You told him he would pay for what he had done to your friends and went and armed yourself with a lethal weapon.

"You are a calculating and dangerous young man."

Gary's mum Elaine, 54, said: "Jamie Munn shot and killed my only son and left my 11-year-old granddaughter without her dad.

"We are heartbroken.

"We will never see Gary's handsome, cheeky face again. It's unbearable. However, justice has been done."

During the trial, the court heard how Munn fixed Gary in the telescopic sights of a hunting gun and shot him from 50 yards.

Witnesses told how they saw Munn lean on a wall to steady his rifle, before the shooting.

Doctors were unable to save Gary.

Munn, of Cochno Road, Duntocher, was convicted of murdering Gary by shooting him in Morrison Street, Duntocher on April 16 last year.

He also found guilty of firearms charges, including having a Tazer stun gun in his home.

Where he got the powerful rifle and what he did with it afterwards remains a mystery.

Munn had a special defence of alibi and told the court he was home in bed when Gary was shot and killed.

Gary Allan, defending, said Munn stills claims he is innocent.