"Crazy Joe" Vallo was a colorful and volatile figure in the mid-20th-century American underworld, known for his unpredictable temper and shifting criminal alliances.

John Wayne Gacy was an infamous American serial killer and rapist who murdered at least 33 young men and boys in the 1970s, famously burying most of his victims beneath his Chicago-area home while maintaining a public persona as a community volunteer and children's party clown.

Jim Jones was the notorious American cult leader who founded the Peoples Temple and orchestrated the 1978 mass murder-suicide of 918 of his followers via cyanide-laced punch in Jonestown, Guyana.

Aileen Wuornos, one of America's most infamous serial killers, shot and killed seven men in Florida between 1989 and 1990 while working as a highway prostitute, claiming the murders were committed in self-defense against sexual assault.

Israel Keyes was a meticulous and chillingly systematic American serial killer who hid "kill caches" across the country years in advance to deliberately evade detection and cross-jurisdictional tracking.