Man found guilty on the murder of Rob Knox, Harry Potter's actor

A man was found guilty on Wednesday of stabbing to death a teenage actor who played a role in the forthcoming Harry Potter film during a frenzied revenge attack.

Rob Knox, 18, died after being stabbed five times outside a bar in Sidcup, southeast of London, in May 2007 as he tried to protect his younger brother Jamie, 17.

Karl Bishop, 22, was found guilty of his murder at the Old Bailey, the Press Association reported. Speaking outside court the actor's mother Sally Knox spoke of her loss and vowed to stamp out knife crime, a major social problem affecting young people in Britain.

"We will work towards making sure he did not die in vain by continuing our work against knife crime," she said.

"We are enormously relieved justice has been done, although there is nothing that will compensate for the shattering sense of loss," Rob's father Colin said.

Bishop of Sidcup, who will be sentenced at the Central Criminal Court on Thursday, faces a life in jail. He showed no reaction as the jury returned a guilty verdict. Earlier on Wednesday he had refused to leave the cells to hear proceedings.

The court heard Bishop had been involved in a row with Knox at the bar the previous week. The following week he returned but was refused entry and ended up in another confrontation with Knox and his friends.

He returned home and armed himself with two kitchen knives. On his way back he came across Jamie Knox, and his brother ran out of the bar when he heard that Bishop was back.

During the altercation Bishop threatened that he "would stab anyone who came near him," prosecutor Brian Altman said.

He stabbed Knox, who had a small part as Marcus Belby in the forthcoming Harry Potter and the Half-Blood Prince. The knife penetrated a main artery and was to prove fatal.

"This man (Bishop) was the aggressor and he was acting out of revenge. He wasn't under attack -- because he had the whip hand," Altman said.

"This man carries knives like others carry pens in their pockets, quite happily thinks little or nothing of stabbing others as if it were some occupational hazard."

The court heard that Bishop showed "absolutely no signs of remorse." When told that Knox had died, he replied: "Yeah, sweet." After the verdict was delivered, Knox's parents burst into tears and were comforted by friends.

Bishop was also found guilty of wounding Knox's friend Dean Saunders, 23, but not guilty of wounding another Tom Hopkins, 19. The jury is still considering charges of wounding involving three others.