A killer who stabbed an innocent boy to death with a pair of scissors has been jailed for at least 15 years.
Connor McMath, 21, struck Sean Ford, 15, in the neck in front of other stunned youngsters.
Prosecutors said the teen had “done nothing” wrong and instead had been a peacemaker after a friend had been assaulted at the flat in North Wishaw, Lanarkshire, on March 7, 2020.
McMath fled the scene leaving his stricken victim, who never survived the attack.
On Friday he was handed a life sentence at the High Court in Glasgow having earlier been convicted of murder.
Lord Matthews told him that “this one act of impulsive violence” had ruined a number of lives.
The judge added: “This kind of thing sadly all too often results in stupid arguments and violence, which, in this case, was sadly fatal.
“The circumstances are even more incomprehensible as there was no need for you to get involved at all.
“You know perfectly well that you were responsible for the death of a child and that must be met with significant punishment.”
The trial last month heard how McMath was “acting hard” before the killing.
McMath joined a number of youngsters at the flat along with 18-year-old Derek Paton.
Jurors heard claims it was there Paton assaulted a 15-year-old boy, who was a friend of Sean.
Sean, of Wishaw, came into the room and stated: “What are you doing that for? That’s my pal.”
As the schoolboy then sat down, McMath suddenly lashed out for no apparent reason.
A 13-year-old girl told the trial: “He took scissors out of his pocket and the next thing I knew there was blood everywhere.”
As a dying Sean begged for help, the killer fled from the flat.
A 999 call was made as a 14-year-old girl gave Sean CPR.
However, the tragic teenager died from a stab wound to the neck.
McMath, also of Wishaw, soon texted his grandfather asking to stay with him.
In a message, he stated: “I have stabbed someone in the neck… like an idiot.”
McMath also confessed to his parents. Asked why he had attacked someone, he replied: “Don’t know.”
McMath denied murder, claiming self-defence and that he had not aimed the scissors at Sean.
But, in his closing speech, prosecutor Chris McKenna told jurors: “Sean Ford had done nothing to justify what happened to him – far from it.
“The evidence suggests he was trying to calm the situation down.”
Donald Findlay, defending, said what happened that night was “desperately unfortunate”.
The QC added: “It is clear he did not start the incident, but he reacted and, as a consequence, someone died.”