There's A Very Good Reason To Be Creeped Out By That Mustached Man On MINDHUNTER

There's a lot to unpack on Netflix's new series MINDHUNTER. Set in the '70s and based upon the book Mind Hunter: Inside the FBI's Elite Serial Crime Unit by John E. Douglas and Mark Olshaker, the David Fincher-helmed show takes us into the early days of criminal profiling, before "serial killer" was a household term. The early episodes of the show focuses on interviews with real-life killer Ed Kemper, but there's one infamous murderer you may have missed that the FBI agents don't speak to. Did you catch MINDHUNTER's reference to the BTK Killer?

At the beginning of episode 2, we are introduced to a man in the cold open we have never met before. He wears an ADT uniform, has thick glasses and a mustache, and is very strict about office supplies. His co-worker calls him "Dennis," but in the credits on IMDb, actor Sonny Valicenti is only listed as "ADT Employee." We don't see Dennis again until the beginning of episode 3, when he is, once again, in Kansas — miles from where are FBI agents are at the time.

It may seem a little random, until you realize that Dennis is actually an infamous serial killer. Or, more accurately, Dennis is about to become one.

Yep, Dennis is the BTK Killer.

According to Biography, ADT employee Dennis Rader killed 10 people in the Wichita, Kansas, area from 1974 to 1991. What's most disturbing about this killer — who received his moniker because of his "bind, torture, kill" M.O. — is that he taunted the authorities who were unable to stop him for years with messages.

Ultimately, Rader's desire for the BTK story to be told is how he was caught: In 2004, Rader resurfaced, sending local media outlets and authorities different items related to his crimes. A computer disc led authorities to Rader's church, and in February of 2005, he was arrested. Rader was sent to El Dorado Correctional Facility to serve his 10 life sentences. He is still alive, and behind bars, today.

By the way, if you're super creeped out, here's a funny video of actor Valicenti promoting MINDHUNTER.

There's something particularly intriguing about MINDHUNTER showing a serial killer living as a free man, despite the crimes he is committing. The audience knows something is wrong with this Dennis character, though only those will a serious knowledge of true crime might be able to pinpoint the BTK killer from his first appearance. It's almost as though MINDHUNTER wants us to become like Jonathan Groff's Agent Holden Ford: Constantly searching for the little clues that indicate someone may have a desire to kill.

Alas, we'll have to wait until season 2 to see how Ford and the BTK Killer cross paths...and until the show ventures into 2005 for the killer to finally receive justice.