Mindhunter Season 2: 9 Serial Killers Confirmed

3. Paul Bateson

Paul Bateson was convicted of the 1977 murder of gay film critic Addison Verrill, which led police to deduce that Bateson was probably also responsible for the infamous "bag murders", where six gay men were killed and dismembered.

Though Bateson was only ever convicted of Verrill's murder, director William Friedkin ended up meeting with Bateson, who helped him form the basis for his 1980 Al Pacino thriller Cruising.

Friedkin didn't just visit Bateson on a whim, though. Here's where it gets really weird: several years prior to the murders, Bateson appeared as an extra in Friedkin's The Exorcist, playing the role of the surgeon's assistant when Regan (Linda Blair) undergoes a carotid angiography at the hospital.

It'll be interesting to see whether or not his appearance on Mindhunter will bear out any nods to The Exorcist. It seems unavoidable, really.

As for the real-life Bateson, he reportedly ended up being released from prison in 2004 due to the failure of the police to convict him of any of the bag murders.