I've concluded there's some other sort of power role out there...but what could it be?

My guesses:

  • Forensic Investigator
  • Commuter
  • Hider
  • Paranoid Doctor/Jailkeeper
Forensic Investigator 'cause as I said, someone was looking into links between people who've been killed and those that voted for them.

Commuter because it's off-the-wall and something Kaycee would totally pick.

Hider because once again, off-the-wall and something Kaycee would choose xD

Paranoid Doctor because Kaycee can.

So really, Forensic Investigator is really the only one I think, but you never know. Keep all these in mind.