TWO young killers, one a martial arts' exponent, systematically kicked a teenager for nearly an hour, by which time his head had swollen to twice its normal size.

At the High Court in Glasgow yesterday, the pair were found guilty of murder.

Karate devotee William Gilfillan, 17, of Mayfield Court, Stirling, was ordered by Lord Gill to be detained without limit of time.

His co-accused, Thomas Blain, 18, of Glasgow Road, Stirling, was ordered to be detained for life.

Both showed no emotion as they were led away to start their sentences for the murder of Andrew McPhail, 17, who stayed in the same block of YMCA flats as Blain.

During the trial, the jury heard there were boot marks imprinted in McPhail's face and body and he had begged for mercy for 40 minutes during the beating in Gilfillan's house.

Gilfillan had bragged earlier that he was going to kill McPhail and invited another youth to watch while he carried it out.

Mr James Scott, prosecuting, told the jury McPhail had been picked on because he was a passive victim who was unable to defend himself and who was crying as the beating began.

Gilfillan told police later that he had used skilled karate kicks on his victim.

Neighbours heard the teenager begging for the beating to stop and then sobbing and moaning. They were too frightened to go for help.

The killing was described by Mr Scott as a ``wicked, reckless assault'' and they did not ``care a whit''.

Gilfillan asked a neighbour to help him ``dump'' McPhail in the close mouth.

Mr Scott said: ``He didn't even try to get an ambulance for the dying boy. Instead, he and Blain washed and changed their bloodstained clothes.''

A pathologist told the jury that McPhail died because the kicking caused his brain to swell, forcing fluid back down his spinal column.

He died in the neuro-surgical unit at Southern General Hospital, Glasgow, five days after the attack as his grieving father sat holding his hand.

The pair initially tried to blame each other for the attack but Gilfillan finally told police what had happened. He was high on drink and drugs and in a foul mood the night he decided to kill McPhail over a small debt, the court heard.