A 15-year-old boy stabbed his friend to death after they snorted cocaine and downed alcohol at a party in Liverpool, a court has heard.
The boy stabbed 16-year-old Luke Howard 12 times as they fought on the floor at a house in Knotty Ash last August.
The pair were with several other boys where they smoked cannabis, took cocaine and drank beer and spirits.
Liverpool Crown Court was told the defendant admitted killing his friend but did so in self-defence.
The court heard how the pair had a History
of bickering with each other and on the night he was killed, Luke repeatedly prodded the accused with a screwdriver.
Richard Pratt QC, prosecuting, said the killer, who cannot be named because of his age, used a kitchen knife from the house where the party was being held to kill Luke.
Luke was taken to Liverpool's Royal Hospital after the attack, but was pronounced dead several hours later.
A post-mortem examination showed he sustained two stab wounds to the head and 10 around his body - two penetrating 14cms (0.4ft) through main veins, muscles and organs.
Mr Pratt said: "In the heat of this particular moment and no doubt fuelled by the effects of alcohol and drugs, this young defendant lost his temper and wholly over-reacted to the situation.
"It may be that shortly afterwards he bitterly regretted what he had done."
The case continues.