A MAN who used martial arts kicks during an unprovoked street attack on a stranger has been convicted of murder.

Luke Quinn, 33, left his victim Simon Richardson dying in the street after an assault which involved knocking him to the ground and then stamping on him as he lay defenceless.

Hours later Quinn, of Busby, East Renfrewshire, boasted to his taekwon do instructor by text about what he had done.

In the message Quinn said: "It's a deadly art. I was surrounded by prozzies and pimps. I did a two strike combo. I was so relaxed. They took him away in an ambulance convulsing, eyes open, body shaking. I suddenly realised what you had taught me is great responsibility."

Yesterday at the High Court in Glasgow a jury found Quinn guilty of murdering Mr Richardson, from Paisley, who died from massive internal bleeding.

Telesales worker Quinn denied murder and claimed he was suffering from diminished responsibility due to Aspergers Syndrome.

He did not give evidence, but he told a psychologist he snapped because he did not like being touched and Mr Richardson had been patting him on the back.

Judge Bill Dunlop QC deferred sentence on Quinn until next month for background reports.

Advocate depute Allan Nicol, prosecuting, told the court that Quinn, originally from South Africa, was deported from Auckland, New Zealand, to the UK after committing a sex offence.

Mr Richardson's mother died six weeks after him on Christmas Day in 2013.