In 1982, when the bodies of 3 women were discovered beneath the surface of Seattle's Green River, no-one realised that it was the beginning of an extraordinary killing spree that would baffle police for 19 years. The 'Green River Killer' would become the most prolific serial killer in US history, claiming the lives of more than four dozen victims, but it would take until 2001 before DNA testing solved the mystery of his identity. To his friends and family, Gary Ridgway was a mild mannered truck painter and a loving husband, but for 19 years he had prowled Seattle's red light areas, picking up young women, strangling them during intercourse, dumping their bodies in the woods, and sometimes returning to have sex with the corpses. Featuring video of his startling confessions - the cops that pursued him, the attorneys who prosecuted and defended him, leading experts, school-friends, and the wife who spent 16 loving years with her dream man, attempt to unravel what had created this monster. Had he been warped by his unusual relationship with mother? Or was the Green River Killer a product of nature - born to kill?