1. The BTK Killer, Dennis Rader
And finally, we have Dennis Rader aka the BTK Killer, who was not-so-subtly introduced in the first season as the "ADT serviceman" briefly featured at the beginning and end of several episodes.
Rader is an especially interesting case because he wasn't actually caught until 2005, meaning that there sadly won't be an opportunity for Ford and Tench to interview him, at least unless the show fudges the facts or carries out a major time jump (one which would probably require quite a bit of make-up).
Rader killed 10 people over a 17-year-period in Kansas, during which time he provoked both the police and media with letters not unlike the famous tauntings of the Zodiac Killer many years prior.
A casting call has reportedly gone out for Kevin Bright, the brother of 1974 victim Kathryn Bright, so it's quite probable he'll instead be sitting down for a chat with the FBI.
It remains to be seen exactly how BTK will figure into the overall fabric of the show moving forward, but his young self will surely make more periodic appearances. If Mindhunter continues for several more seasons, perhaps a series of time jumps will nudge us forward to his eventual capture. Anything can happen, basically.
What do you think of the roster for Mindhunter's second season? Shout it out in the comments!