NBC's The Office ran for nine seasons after it debuted in 2005 as an American remake of a British sitcom, and over the years it featured quite a few long-running gags and inside jokes that captivated viewers long after the series ended. However, it's the mystery of the Scranton Strangler that has really kept fans guessing.

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The serial killer first appeared in a newspaper headline during the sixth season episode "The Delivery," though the Scranton Strangler would soon become a consistent mystery that haunted the staff of Dunder Mifflin and the town of Scranton for the remaining seasons. A number of fan theories popped up regarding the Scranton Strangler's true identity, but only a few managed to add up.

Adds Up: Gabe Lewis

Zach Woods as Gabe Lewis on The Office

While there isn't a lot of evidence pointing towards Gabriel Susan "Gabe" Lewis (played by Zach Woods) besides his creepy manner and proven inability to handle rejection after his failed romance with Erin, the timing of his arrival in Scranton is definitely suspicious.

Following the sale of Dunder Mifflin to Sabre in the sixth season, Gabe arrives at the office to oversee the transition at around the same time that the Scranton Strangler murders start. The suspicious timeline could a coincidence, but also, he's a Gabewad.

Makes No Sense: Dwight Schrute

Dwight-Schrute-in-The-Office

There are quite a few fan theories that point towards Dwight Schrute (played by Rainn Wilson) as the Scranton Strangler due to a number of red flags throughout the series, however, he's almost too convenient of a suspect given his unique eccentricities and upbringing.

Despite actually dressing as the Scranton Strangler for Halloween, Dwight has also actively attempted to hunt down the Strangler with groups like the Knights of the Night, and his overwhelming sense of duty and justice doesn't lend itself to the mindset of a serial killer, especially considering his legitimately close friends in The Office.

Adds Up: Creed Bratton

Creed Bratton with a bloody shirt in the Office

One of the most mysterious characters in The Office is "Creed Bratton" (played by the musician of the same name), who became a possible frontrunner for the Scranton Strangler after more than a few truly odd moments from the Director of Quality Assurance.

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The mystery behind his name is due to the revelation that he isn't the original Creed Bratton and merely assumed the name. He also has a laundry list of oddities that include his penchant for death-smelling mung-bean sprouts, his history with religious cults, his past alleged murders, and when he showed up covered in blood without realizing it was Halloween.

Makes No Sense: Ryan Howard

Ryan Howard looking at the camera while taking notes in a notebook in The Office.

Ryan Howard (played by B.J. Novak) is also an easy target like Dwight, as he has proven over the course of the series to be vindictive (he made a revenge list of people who had crossed him) and has a history of drug abuse that led to wild mood changes, not to mention his numerous sociopathic tendencies.

However, regardless of his numerous flaws and troubling characteristics, Ryan is also fairly spineless and definitely lacks the edge of the Strangler. There is also almost no evidence connecting Ryan to any of the Strangler murders in Scranton, making this theory hard to believe.

Adds Up: Andy Bernard

Ed Helms as Andy Bernard in The Office

One of the more surprising theories that makes more and more sense upon further review came from a Reddit user who posits that Andy Bernard (played by Ed Helms) could be the Scranton Strangler due to a possible undiagnosed Disassociative Identity Disorder.

The theory goes into detail that Andy is the dominant personality that constantly struggled with other personas like the angry Andrew, Drew from Cornell University, and the wild Nard Dog that could have led to a final, deadly persona. Plus, Andy's influential family could have pressured the jury (which included Toby) that convicted the supposed Strangler.

Makes No Sense: Robert California

There are a few fan theories that presume former Dunder Mifflin manager/Sabre CEO Robert California may have been the Scranton Strangler, despite the fact that James Spader didn't join the cast until well after the Strangler was first mentioned.

However, the theories persist due to California's odd behavior, multiple identities (both California and Bob Kazamakis appear to be aliases), and the interesting choice of song played by California and his assembled musicians in "Pam's Replacement" - The Rolling Stone's "Midnight Rambler," which was loosely based on the Boston Strangler.

Adds Up: Rolf Ahl

Dwight's best friend (before Pam) was an odd character named Rolf Ahl (played by James Urbaniak) who first appeared in "Company Picnic," where he quickly displayed anti-social behavior, violent tendencies, and anger towards women.

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Dwight revealed he met him in a shoe store where he was searching for a shoe that would make him speedy while also leaving no tracks behind which should have been a clear red flag, among other creepy issues that are well outlined in this Reddit theory. Toby even seemed like he was about to reveal Rolf's name to the camera as a suspect before Dwight walked into the room.

Makes No Sense: Mose Schrute

Michael Schur (TV writer, producer, and creator of series like Parks & RecBrooklyn Nine-NineThe Good Placeappeared occasionally on The Office as Dwight's cousin Moseproving that Dwight isn't actually the weirdest member of his family.

Mose lives at Schrute Farms and is definitely a quirky individual who makes interesting wood carvings, has terrifying nightmares and likes to wear the mask of a potential serial killer. However, he is also kind-hearted and likely isn't the Scranton Strangler. Probably.

Adds Up: Toby Flenderson

Toby from The Office

One of the likeliest suspects for the real Scranton Strangler is Toby Flenderson (played by writer, executive producer, and later showrunner Paul Lieberstein), former Human Resources administrator for Dunder Mifflin's Scranton branch.

Toby was absent from the office during the Strangler police chase (who was driving what appeared to be Toby's vehicle), and he even helped put George Howard Skub behind bars for the crime, who later attacked Toby when he visited him in prison. Toby stated he told Skub he thought he was innocent, though theorists believe he really revealed his identity as the Strangler.

Makes No Sense:  George Howard Skub

The police chase on Toby's computer in The Office

Sure, George Howard Skub was arrested after a televised car chase with the police after the investigation into the killings led them directly to his door, and yes, he tried to strangle Toby after the former juror visited him in prison, and unavoidably, he has "a devil name."

However, if Skub was really the Scranton Strangler, then that would mean that all of the fan theories and teases throughout the series were either misdirections or imagined by the fans, and that's just no fun at all.

NEXT: The Office: 5 Reasons Why Andy Is The Scranton Strangler (& 5 Why It's Jim)