Keith Johnson was a friend of Derek Warner. In October 1985, Keith, Derek and Harry Mowlam robbed a security van, witnessed by Sandie Merrick. The police investigated the robbery. Harry bragged about his new-found riches, worrying Keith and Derek, as the police were looking for the culprits. Derek initially got Keith to ruff Harry up a bit to keep his mouth shut. Harry was murdered in January 1986, initially thought to have been by Matt Skilbeck but later revealed to be Derek. After this, Keith began helping himself to the loot and getting caught on numerous occasions. In April 1986, Derek found Keith digging up the loot yet again, and held him hostage with a gun. Sgt MacArthur soon arrived as he had suspected they robbed the security van and the pair made a run for it. Derek got away but Keith wasn't so lucky and was caught. Later that night, Derek was caught and then arrested, and confessed to Harry's murder. Keith was jailed for his part in the robbery and Derek was jailed for his part in the robbery as well as Harry's murder.