 His nickname, Jigsaw John, originated in his early career with a dismemberment murder he solved in Griffith Park in which the victim had been cut up jigsaw-style.The moniker caught on because of his ability to piece clues together in difficult cases, resulting in many arrests and convictions.He became an authority on serial murders and worked 12 of them, including the 1950s serial killer Harvey Glatman, Night Stalker Richard Ramirez, the Hillside Stranglers, the Southside Slayer, and the William Bonin Freeway Killer case.