Every year more than 550 people are unlawfully killed in England and Wales. Who are these people, and how and why did they die? Since the motives for murder are many and varied - from domestic to serial sex killing - the techniques of tracking the killer and proving the case must be equally flexible. Working closely with one of London's murder squads, the authors investigate the business of murder, examining police techniques and increasingly sophisticated scientific processes, such as DNA analysis and psychological profiling. Taped interviews with murderers give added insights. Tate has researched, produced and directed documentaries for "The Cook Report" and is the author of "Children for the Devil: Ritual Abuse and Satanic Crime" and "Child Pornography: An Investigation". Ron Wyre is the director of a clinic for sex offenders, and wrote "Women, Men and Rape".