Known in London as the "Gay Slayer", Colin strived to be known as a serial killer. For this purpose he strangled five homosexual men. Robert Ressler states in "However Fights Monsters" that one has to commit five murders to become a serial killer. Colin read the book and used it as a manual in his quest to become a serial killer. He meticulously planned each murder as he set out to become a famous serial killer. He chose gay sado-masochistic men because they were willing to get tied up. Also, he believed that the public would feel less sympathy for them. Before his arrest he taunted the cops with rambling calls claiming responsibility for the murders and threatening to keep striking once a week. He even stated "I have got the book, I know how many you have to do..."
It is rumored that Colin has killed again in prison. A high ranking Metropolitan Police Officer told unnamed sources to the Archives that Colin had strangled a convicted child murderer in his cell, but because he was serving life with no possibility of parole it was a waste of time and money to prosecute him. The murder was carried while Colin was in Wakefield Prison, Yorkshire. Two weeks after, he was moved to Whitemoor Prison, Cambridgeshire where we hope he stops killing.