A teenager has been found guilty of murdering a school friend he claimed had pestered him for sex.
Craig Roy, 19, was convicted over the death of 16-year-old Jack Frew in woodland near their school in East Kilbride, South Lanarkshire, in May 2010.
He stabbed the younger boy 20 times and slashed his throat with a kitchen knife.
Roy had cheated on his long-term boyfriend with Jack and was plagued by guilt over his infidelity, the trial at the High Court in Glasgow heard.
He admitted stabbing Jack but denied murder, claiming he had no memory of the incident and that he had taken a knife with him to meet the victim because he wanted to scare him.
Roy said he only recalled taking out the knife and then seeing Jack lying bleeding to death on the ground.
But instead of calling an ambulance for the dying teenager, Roy called his boyfriend for help for himself.
Roy claimed Jack had been blackmailing him for sex after they shared a sexual encounter in the school toilet three months before the murder.
He said the schoolboy, described by friends as "flirtatious" and "flamboyant", was a "sex pest" who would threaten to tell Roy's boyfriend he had cheated.
Roy was the only person in the three-week trial to make the claims. He said he took a knife to the meeting in secluded woodland on May 6 in order to "scare" the younger boy into leaving him alone.
But instead he attacked the openly gay teenager, leaving him with horrific wounds including punctured lungs, a cut windpipe and knife damage to his ribs.
Roy's defence said he had a personality disorder which diminished his ability to control his actions.
But the jury of nine women and five men rejected this claim, finding him guilty of murder after almost two hours of deliberation.
Area Procurator Fiscal for Lanarkshire Janet Cameron said: "Craig Roy armed himself with a knife and carried out a violent, sustained and murderous attack on Jack Frew.
"Jack Frew died because Craig Roy had a knife and had no hesitation in using it and using it repeatedly.
"This crime yet again demonstrates the devastating consequences that can follow from carrying a knife.
"The senseless loss of such a young life is tragic and caused shock and concern, not just to the local community in East Kilbride but across our country.
"Today's conviction should act as a warning to anyone thinking of leaving home with a knife or using a knife that prosecutors, working together with the police, will ensure that those people are caught, prosecuted and brought to justice.
"Our thoughts remain with the family of Jack Frew at this time."
As the unanimous verdict was announced, Jack's family and friends threw their arms around each other, sobbing.
On the other side of the almost-full public gallery Roy's friends and family sat silently.
Roy wore a black suit with a white shirt and grey tie as he sat in the dock. When the verdict was read out he kept his head bowed and said nothing. He did not appear to make eye contact with any of his family as he was led away from the dock.
Lord Doherty said Roy would be sentenced on March 1 at the High Court in Edinburgh.