James Richards had a reputation as a dangerous man with a history of violence stretching back to his teenage years

He was given eight years' youth custody in 1987 for carrying out an aggravated burglary in London.

He had threatened an elderly woman with a knife and an axe during a robbery in which jewellery and cash were stolen.

In 1996, he and three others raided a shop in London.

Richards threatened the manager with a gun.

He also has other convictions for burglary and handling stolen goods.

Both Mandy Stephenson and Lynda Cole, who were yesterday found guilty of conspiracy to pervert the course of justice, told police they believed Richards was behind a horrific beating which took place a month before the stabbing of PC Thompson.

The victim, who has not been named, had his lip ripped from his face and 18 teeth knocked out in a savage attack with a hammer.

Cole wept in court as she said she had seen the victim but he had been so terrified he refused to tell police and had left the area.

Stephenson was so frightened she refused to give evidence against Richards during the trial. Her son, Shaun Kelly, also refused to give evidence.

The jury was played tapes of police interviews in which she frequently broke down in tears as she told them why she had lied to them about her involvement on the night of the stabbing.