Warning: spoilers ahead for Mindhunter Season 1! Read forward at your own risk!
Between 1995's Se7en, 2007's Zodiac, and now the new series, Mindhunter, it's pretty clear that David Fincher knows how to get into a killer's head. The freshman Netflix series took Jonathan Groff's increasingly cocky agent Holden Ford to some dark places in its first season, culminating in an Ed Kemper-induced panic attack that closed out the current arc. Holden's progression into darkness has led some viewers to theorize that he could become a killer himself, but Groff sat down with me at a recent Netflix press event and admitted that he's confused by those fan theories. The Frozen star explained:
The rationale for this fan theory stems from a few specific pieces of "evidence" that have popped up over the course of the Mindhunter's first season. Some have argued that Holden Ford meets many of the clinical requirements of a psychopath, as far as what's laid out by the show. His lack of empathy (coupled with his possibly troubled relationship with his mother) may suggest that he's not nearly as far away from a guy like Ed Kemper as he would want to admit.
That said, the progression of Holden's character and psyche is rooted in the trauma faced by real-life FBI profiler John Douglas. It's meant to show the dark ways that this experience affects Holden -- not necessarily to telegraph him eventually becoming a serial killer himself. Considering how many TV shows embrace plot-altering twists like that, it's perfectly reasonable for people to make such assumptions.
Beyond feeling baffled by the theories that Holden Ford could become a serial killer in Mindhunter Season 2 (which is reportedly in the works) or beyond, Jonathan Groff also told me that he doesn't think the FBI profiler has descended nearly as far as some have suggested.
In the end, it might be for the best that Holden isn't going as dark as some fans have assumed. For him to become a full-blown killer at some point during Mindhunter's run might read a little too close to the ending of Se7en -- which similarly sees Brad Pitt's Detective David Mills becoming the monster he was investigating by murdering serial killer John Doe. Holden's experiences with these killers is messing him up pretty badly, but we will have to wait and see exactly how this pans out as the show progresses.