This Mindhunter Theory About Debbie & The BTK Killer Makes SO Much Sense

This post contains spoilers about Netflix's Mindhunter.

If you've been watching Mindhunter, Netflix's new series about an FBI agent who tries to understand the minds of serial killers, you probably have a few questions. The show is inspired by John E. Douglas' book Mind Hunter, which details the 25 years Douglas himself spent in the FBI. (Jonathan Groff's character, Holden Ford, is loosely inspired by Douglas' experiences.)

And the BTK Killer — a.k.a., that creepy ADT home security guy who keeps showing up at the beginning of Mindhunter episodes — is inspired by a real-life person, too. Dennis Rader, a real-life serial killer, earned the nickname "BTK Killer" because he bound, tortured, and killed his victims.

But could Mindhunter be taking some liberties in its portrayal of the BTK Killer?

According to Redditor MacrobionicS, the BTK Killer, played by Sonny Valicenti in the Netflix series, could be Debbie's (Hannah Gross), father in the show.

MacrobionicS has two points that may be evidence Mindhunter could go that route.

"In the first episode, Debbie is there to see a band from Detroit. BTK's daughter was living in Detroit when FBI showed up at her house to tell her that her father was BTK and that her medical records and pap smear had been used to find a familial match," MacrobionicS explains. "The night before BTK was arrested, he and his daughter spoke on the phone and he reminded her to get the oil changed in her car. Debbie forgets to put oil in her car and her engine seized, which is why Patrick gave her a ride. Holden gives her a hard time about this and she says something like 'my dad used to remind me to change the oil, maybe you can do the same thing.'"

Still, we might not see a resolution for Valicenti's character on screen anytime soon. Holt McCallany, who plays Bill Tench on Mindhunter, suggested to Refinery29 that the series might play the long game with Rader.

"He was literally at large for 30 years! We try to remain true to the details of the crimes... Let's hope to God that we get to do this for five seasons. [But] we may never catch the guy. Our journey begins in 1978, are we really going to go up to 2005? I don't think so. We'll span a number of years, but not all of those years," McCallany told Refinery29. "These guys don't solve all of their cases. You don't get to solve them all in real life, and you don't get to solve them all in Mindhunter. You would never see that on a network show."

So unless the show jumps several decades over the course of its future seasons, we might not see the BTK Killer apprehended on screen. Plus, we already know that Mindhunter season 2 will focus on the Atlanta child murders, so it's not clear how big a role the BTK Killer will have in the second set of episodes.