A teenager who murdered a former friend by stabbing him 12 times in the back has been jailed for life with a minimum term of 16 years.
Macauley Jenkinson was 16 when he launched a ferocious attack on Michael "Angel" Graham, 19, on the Scarborough seafront in April.
Jenkinson, now 17, of Main Street, Seamer, had bought the flick knife earlier that day and laughed on hearing his victim had died.
After a two-week trial he was convicted at Teesside Crown Court by a majority of 11-1 of murder, and wounding with intent another teenager.
Mr Graham and his killer fell out after he taunted Jenkinson for dating a 14-year-old girl when the defendant was a year older.
There was name-calling and abusive texts, described by the Judge Simon Bourne-Arton, the Recorder of Middlesbrough, as "adolescent posturing".
Then Jenkinson bought the knife, gathered a gang of supporters and went looking for Mr Graham.
It was when his victim was fighting another teenager on the seafront that Jenkinson struck, stabbing him hard in the back a dozen times.
"As the coward you are, you waited until his back was turned to you and he was defenceless," the judge told Jenkinson.
"On hearing of his death you were laughing, you were joking, you were calm."
A boy, who cannot be identified and who went to help Mr Graham, was also stabbed in the leg.
The judge lifted reporting restrictions on the media identifying the defendant because of the public interest in the case.
Detective Chief Inspector Maria Taylor, of North Yorkshire Police's Major Crime Unit, said: "The sentence handed down ... reflects the seriousness and brutality of Jenkinson's actions.
"I hope that Michael's family can now feel some sense of justice and can try and begin to rebuild their lives."