Cinema is full of monsters, but none is more horrifying than the serial killer, because serial killers cannot easily be wished away by the belief that it’s ‘only a movie’. Sure, they might just be deeply damaged human beings, but there are a lot more of those in the world than skyscraper-sized reptiles or interplanetary demons. Even while watching a work of fiction, there is no quarter from the idea that somebody, somewhere, may want to kill you – and for no other reason than some unknown psychological force compels them to do so.

These films hold a cracked mirror up to society itself and often focus on observing the conditions that allow serial killers to exist. They descend into the darkest parts of humanity, and in doing so reveal some things about ourselves we might not want to admit. You’re guaranteed to leave shaken.