Christopher Berry-Dee is a bestselling writer and acknowledged authority on serial killers. Several of his books are required reading for students at the FBI's Behavioral Science Unit. He interviewed both Ross and Bianchi in prison and witnessed Scripps's execution in Changi jail; and he has received the full cooperation of numerous law-enforcement agencies, including State Police in New York and Connecticut, Singapore Police, and HM Customs and Excise Special Investigations.