A youth convicted of stabbing a Hornchurch man at the Notting Hill Carnival in August has been detained for four-and-a-half years.

Junior Henry, 17, had a string of previous run-ins with the law and was on bail when he knifed 20-year-old Rio Andre in the stomach at the West London event.

Henry, of Shepherds Bush, had been cleared of murder after being involved in gang violence which led to the death of someone, who was not involved, when he was 12.

Henry was convicted of conspiracy to commit grievous bodily harm and violent disorder. He was given a three-year supervision order when the trial of gang members ended when he was 14.

Since that May 2009 sentencing, the court had varied the order in November that year and in March this year after breaches.

In July this year, aged 16, Henry was convicted at a youth court for attacking another youth. While on bail awaiting sentencing, he stabbed Andre at the Notting Hill Carnival.

The Recorder of London Judge Peter Beaumont, sentencing him at the Old Bailey on Thursday last week, said: “You left this court with my warning ringing in your ears that your behaviour was challenging the boundaries of the order, as well as testing the patience and understanding of the court.

“You did not heed the warning. You took up a knife in circumstances where you, of all people, did not have to use it and you knew the consequences of doing so.”

The judge lifted an order banning publication of Henry’s identity, and sentenced him to 54 months’ youth detention.