By News Editor Declan Wilkes

A man has been sentenced to life for stabbing teenage Harry Potter actor Rob Knox to death outside a bar in Sidcup.

Karl Bishop, 22, from Sidcup, knifed the 18-year-old after a fight outside the Metro Bar last May - he received three further concurrent life sentences for wounding four others.

The murderers face was "screwed up with rage" arming himself with two kitchen knives and lashing out at the victim and his friends, witnesses said.

The court heard he was looking for "revenge" as he had lost a fight with Mr Knox and his friends the week before the killing.

Bishop denied murder and five counts of wounding at the Old Bailey.

"You didn't care if you killed him"

Sentencing, Mr Justice Bean told Bishop that he was a highly dangerous man. Adding:

"I do not think it is proved that you intended to kill Robert Knox. The truth is that you simply could not care less whether you killed him or not," he said.

"Your lack of regret let alone remorse was truly chilling".

Bishop was convicted of wounding the actor's friends Dean Saunders, 23, and Andrew Dormer, 17, and wounding with intent to cause grievous bodily harm to Charlie Grimley, 17, and Nicky Jones, 20 - but was found not guilty of wounding another friend, Tom Hopkins, 19.

Knifed five times

Mr Knox was knifed five times as he rushed outside the bar to defended his little brother Jamie from Bishop, the court had heard. Five other people were also stabbed in the fight.

The prosecution called Bishop an "habitual knife carrier" who thought of stabbing people as an "occupational hazard" and had previous convictions for knife crime, Mr Altman said.

Mr Knox's parents were present in court for the verdict.

'Released to kill'- officer given written warnings

Its emerged that Bishop had been sentenced to four years for GBH but had been freed early on parole before the murder.

Karl Bishop had served 18 months before his release and his licence period ended weeks before he killed the actor in Sidcup in May last year.

Two police officers have been issued written warning after Scotland Yard confirmed that Bishop was a suspect in an attempted robbery in March 2008 but had not been arrested due to insufficient evidence.

The Met added that the case was still being investigated when Mr Knox was killed.

Mr Knox, from Swanley, Kent, played the part of Marcus Belby in the film Harry Potter And The Half-Blood Prince.