John Wayne Gacy and Ted Bundy Were in This “Club.” But Not All Serial Killers Are.

In his book Defending the Devil, Ted Bundy’s criminal defense attorney said his client’s murderous ways began as a child in Tacoma, Washington. He started with animals. The future serial killer would buy mice at a local pet shop, build a little corral in the woods, and “play God” to decide which of them he’d kill and which he’d let go. He later used the same approach with women.

Boston Strangler Albert DeSalvo reportedly trapped dogs and cats in wooden crates and shot them with a bow and arrow. Chicago serial murderer John Wayne Gacy allegedly lit live turkeys on fire after dousing them with a gasoline-filled balloon. Other members of the animal-torturing-before-serial-killing “club” include Carrol Edward Cole (who strangled puppies and people), Robert Bordella (the “Butcher of Kansas”) and John Norman Collins, who strangled cats before he started throttling women.

This link has been used for decades to argue that budding serial killers often begin their criminal careers as children, first by targeting animals and later “graduating” to humans. Further support for the link between animal and human cruelty are the myriad examples of adult serial killers who tortured and killed humans in similar ways similar to how they had hurt animals as children.

But here’s where it gets complicated. Not all serial killers abuse animals first; depending on the study, estimates range from twenty-one to seventy-three percent. And, as you’re…