Youth sentenced to life for knife murder of schoolboy

A 16-year-old youth was today sentenced to life for murdering the schoolboy Martin Dinnegan last June.

Joseph Chin will serve a minimum of 12 years in prison for stabbing his 14-year-old victim in the back four times in north London.

The attack happened following an exchange of "dirty looks" between two groups of teenagers in Holloway. Dinnegan tried to outrun his pursuers, shouting "Please help me" to passers-by as he fled.

"This was a deliberate attack requiring a long chase with revenge in mind," said the judge, Brian Barker.

"It was an attack carried out without any regard to the standards and rules that we live by and no thought for the victim, his friends and his family.

"It is a tragedy that this sort of triviality caused such a young man to lose his life and has caused enduring heartache to his friends and family."

Dinnegan's parents, Lorraine and James, who have called on Gordon Brown to tackle Britain's rampant knife culture, were at the Old Bailey with their eldest son to see Chin jailed.

The teenager can be named for the first time after a court ban on identifying him was lifted. He was unanimously convicted of murder by a jury last month.

Chin's friend Kevron Williams, 17, was convicted of attempting to cause grievous bodily harm with intent during the same attack, and was sentenced to four years' youth detention.

Dinnegan, a pupil at St Aloysius College in Highgate, was the 15th teenager murdered in London in 2007. He had moved to London 11 years ago with his parents from his mother's hometown, Glasgow.

During the trial, Aftab Jafferjee QC, prosecuting, said teenagers showing off in front of their friends and being prepared to use violence had become a scourge of cities and towns. "This is such a case, which leads from dirty looks to death in one hour," he said.

Chin stabbed Dinnegan after being knifed twice himself during a series of flare-ups between the two groups.

The teenager had a criminal record dating back to 2004, including the possession of a snooker ball in a sock and threatening a man with a hollow bar.

"You have shown a tendency to use violence when it suits you," the judge told Chin. "The public have every right to be concerned about the increase growth of this sort of violence."