For a long time, it felt like crime procedural TV shows were worn out and overexposed. And then Netflix's Mindhunter came along. Mindhunter is a period crime drama that covers the development of the FBI's Behavioral Science Unit, and this fictionalized version of real-life events is a thrilling, fascinating, and a truly unique TV show.

It undoubtedly helps that Mindhunter is rooted in reality. It's very compelling to watch the main trio of characters (Holden Ford, Bill Tench, and Wendy Carr) conduct interviews and investigate some of the most notorious serial killers of all time. And it's even more interesting that the concept of a serial killer didn't exist until they (or the real people their characters are based on) created it. But it is still a fictionalized version of real events.

Some of the show's story lines and plot twists are actual 100% fact, while some of the story lines are creative liberties that have been taken by the writers. So here are five true facts you can find in Mindhunter, along with 5 things they took creative liberty on.

Fiction: The Real Bill Tench's Son Never Witnessed A Murder

Mindhunter Season 2 cast members standing together

Although Mindhunter is a fictionalized account of the development of FBI investigations into serial killers, the two main characters are inspired by real-life people. Bill Tench is inspired by FBI agent Robert Ressler but there are significant differences.

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First off, Ressler had three children, not one. Secondly, none of his children ever witnessed a murder, let alone any murder as gruesome and shocking as the one that Bill's son Brian is a witness to in season 2 of Mindhunter.

Although Ressler spent most of his life elbow-deep in horrifying crimes, I'm sure he was grateful that none of his children were ever subject to them.

Fact: The Crucifixion Resurrection

Holt McCallany and Jonathan Groff in Mindhunter Season 2

Obviously, the subplot about Bill Tench's son witnessing a toddler being killed and trying to bring him back to life by crucifying him is a pretty extraordinary coincidence, but there is actually some true inspiration behind that horrific idea.

Apparently in San Francisco in the early 1970's a pair of young brothers killed a 20-month old boy because the boy wouldn't stop crying, and once they realized that he was actually dead the elder brother hung up the deceased child in the way he had seen Jesus Christ on the cross, because he thought if he did so it would bring the boy back to life.

Fiction: William "Junior" Pierce's Interview

Jonathan Groff and Anna Torv in Mindhunter Season 2

The serial killer interviews in Mindhunter are some of the most interesting and memorable scenes in the entire show. They're memorable because seeing so many recognizable names and faces in action is always intriguing, but also because the serial killer characters are really unique weirdos.

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And the same can be said for William "Junior" Pierce, despite the fact that only the biggest true crime buffs have probably ever heard the name before. This ignorant junk food junkie was one of the more memorable killers in season 2, however, the real-life Pierce has never been interviewed by the FBI's Behavioral Science Unit.

Fact: The Elmer Wayne Henley Story

Ted Gunn from Mindhunter

As completely absurd as the entire yarn sounds, the story of one of Mindhunter's season 2 interviewees is entirely real. When the real Elmer Wayne Henley was in his mid-teens he met a serial killer by the name of Dean Corll. Corll initially enlisted Henley to help find him children that were ostensibly being collected for other purposes, but eventually, Henley began participating in the murders with Corll.

Henley participated in half a dozen of the murders that Corll had committed, but after Corll attacked Henley himself Henley finally shot and killed Corll. His willingness to go along with the murders is still completely incomprehensible, though.

Fiction: Mindhunter Didn't Just Magically Find Murderer Doppelgangers

Damon Herriman as Charles Manson in Mindhunter and Once Upon a Time in Hollywood

The production value on Mindhunter, in general, is undeniably top-notch. But their ability to find actors to perform as real living, breathing (or at least formerly living and breathing) serial murderers whose faces the audience has seen a million times seems to be absolutely extraordinary.

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When you look at the actors who play characters like David Berkowitz or Charles Manson it's almost difficult to differentiate between the actor and the real person. And while the actors who play the roles are undoubtedly insanely talented, they are also being helped out by a lot of different prosthetics and makeup techniques to make them look like their characters reincarnated.

Fact: BTK Was A Bit Of A White Whale For The FBI

Mindhunter BTK Killer Real Life

One of the most interesting subplots in Mindhunter is the continuing Easter eggs about an active serial killer in Kansas, who we've come to know in season 2 is Dennis Rader, AKA the BTK killer. It will be intriguing to see where the show takes this storyline though because although BTK was active around this time he wasn't actually caught until many years later in 2005.

Although BTK became less active for quite a while before he was caught, it was a cold case that left the FBI and all of the other agencies who investigated BTK desperate for answers they just couldn't find.

Fiction: They Didn't Perform Every Interview

Mindhunter Cast Characters Real Life

One of the most compelling parts of Mindhunter as a series is the insane interviews that the main characters conduct with violent criminals like Charles Manson, Tex Watson, and Ed Kemper.

While Mindhunter actually does stick to the script very closely when it comes to translating real interviews with these serial murderers from reality into the TV show, many of the interviews seen weren't actually conducted by Robert Ressler or John Douglas, the real-life people who inspired the characters of Holden and Tench. But it's easy to see why the show would change things up, it's much more interesting and much easier to follow if it's Holden and Tench doing all of the dirty work.

Fact: David Berkowitz Did Fake Insanity And Then Retract It

Mindhunter - David Berkowitz

David Berkowitz, better known as the Son of Sam, is not the first serial murderer to pretend that the devil made him do all of the horrible things he did, and he certainly won't be the last. And it's true that he pleaded guilty to all of the crimes he committed even though he claimed that a demonic dog was the one who made him do all of those things.

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But after running with this whole demonic possession storyline for quite a while, he eventually confessed to a psychiatrist that he was speaking to that the entire idea was a hoax.

Fiction: David Berkowitz Didn't Consult On BTK

Albert Jones and Jonathan Groff Mindhunter Season 2

It's safe to say that although serial murderers are abhorrent nightmares that should be stopped at any cost, there are some tidbits of information that can be gleaned from them that could be helpful when it comes to the search for people like them. And clearly Holden and Tench subscribe to that philosophy.

It's no real surprise that Holden and Tench use their serial killer resources to gain insight into other killers, however, the scene where they ask David Berkowitz for his opinions on the BTK murders is pretty much entirely fictional. BTK had been mentioned to Berkowitz in an interview once, but that's about as far as it went.

Fact: Wayne Williams Has Never Been Charged With The Atlanta Child Murders

Mindhunter Wayne Williams and Real Williams

Most TV and film writers don't include a little post script title card with an explanation of where the story went afterward unless it's factual information about this fictionalized event. And while it would be amazing if the tidbit of info that ended season 2 of Mindhunter was false, unfortunately, it's not.

Wayne Williams is still the prime suspect in 23 child murder cases in Atlanta, but he has never been charged with any of those crimes. It's probably cold comfort to the parents of all of those children who were killed, but at least Williams is still in prison on a life sentence for the murder of two adult men.

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