In 2009, Joshua Zeman made Cropsey, a documentary about an urban legend bogeyman who proved to be all too real. It is generally regarded as one of the scariest documentaries ever made; you should watch it if you’re in the mood to be terrified by real-life murders. However, as it’s about an all-too-human killer and not about haints and spookums, it falls a little outside the purview of this list.
His 2014 follow-up, Killer Legends, skews a little closer to paranormal content while still keeping a foot in the arena of your basic, everyday human murderers. This documentary examines for different well-known urban legends – razor blades in Halloween candy, the babysitter and the killer upstairs, the killer with the hook, and scary phantom clown sightings – and looks for real-world origins behind them. While such legends have been the inspiration for horror movies, such as When a Stranger Calls, the film’s possible explanation for the story of the hooked killer delves into the history of the real-life Phantom murders that directly inspired the film The Town That Dreaded Sundown. And while killer clowns may remind you of Stephen King’s It, the documentary is quick to reassure you that ancient shape-shifting monsters aren’t real, but John Wayne Gacy definitely is. So even though the film may help calm fears somewhat about supernatural killers and otherworldly clowns with devious intentions, it will definitely make you more nervous about the seemingly normal humans around you.