Deadly Legacy, Investigation Discovery’s new crime show re-investigates the case of John Wayne Gacy, the infamous serial killer responsible for the deaths of more than 30 men in Chicago in the 1970s. Killer clown John Wayne Gacy was caught in 1978 and executed in 1994. However, the case doesn’t end there. Gacy took the secret identities of eight victims to his grave. The limited series, which airs in three parts, pries open the decades-old file and hopes to confirm the identities of those victims. Cook County, Illinois cold case detective Sergeant Jason Moran believes new DNA technology will make that possible.