"The Butcher of Balin" was the name given to a joined Trill who committed multiple vicious murders during Trill's pre-industrial past. So heinous were his crimes, it was believed that he had been possessed by evil spirits. This killer was caught by an early joining of the Gard symbiont. (DS9 - The Lives of Dax short story: "Allegro Ouroboros in D Minor")
- There's no precise dating for the era this murderer existed in, other than it was before Trill had harnessed electricity or devised criminal psychology. Depending on how literal or widespread the belief in evil spirits was, this could be significantly far back in Trill history.