The Watcher's John Graff family massacre is based on shocking true story

Netflix's new series The Watcher is creepy enough to watch as it is, but it's made all the more horrifying by the fact that the massacre of John Graff's family is actually based on a true story.

Poor Dean and Nora. They just wanted a nice house in the suburbs where their kids could play in the garden, and instead they have to live in fear of being constantly watched by someone demanding 'young blood' and accusing them of being greedy.

Admittedly they probably didn't need as many rooms as they got, and they could really work on closing their curtains, but it's still unnerving.

Netflix's The Watcher has captivated viewers with its mystery of who is sending letters to the new homeowners at 657 Boulevard – a story that itself is based on real events.

The letters aren't the only part of real life that creator Ryan Murphy has drawn on for inspiration, though. In episode three, titled Götterdämmerung, Dean (Bobby Cannavale) learns about the tragic and terrible events that took place in the home before he moved in.

His private investigator details how former homeowner John Graff also received letters from The Watcher, and after losing his job and his grip on family life he eventually took a dark turn and shot his whole family.

Netflix

It's not exactly the happy background you'd want for your new house, and while this story did not really unfold at 657 Boulevard, it did happen in the same town of Westfield.

The events took place on 9 November, 1971, when John List killed his entire family after having lost his job and, like Graff, was relying on his mother's savings for money.

It's rumoured that List made himself lunch between killing his family members, and police didn't find their remains until nearly a month after they were killed, when neighbours voiced concerns.

List had cut his face out of all of the family's pictures and left a note claiming that he killed his family to protect them from an influx of evil in the world, before going on the run.

He wasn't arrested until 1989, after his crimes were detailed in an episode of America's Most Wanted and a woman realised List looked like her neighbour, Robert Clark. He was convicted for the murders and sentenced to five life terms in prison.

Graff's story in The Watcher doesn't end quite so neatly, as Dean learns that the killer disappeared, never to be seen again – that is, until he fancied himself a snack back in the kitchen of 657 Boulevard.