THE ZODIAC KILLER DOCUMENTARY: Unsolved for over 40 years

The Zodiac Killer was profiled by John Douglas in his book, The Cases That Haunt Us, as being a narcissistic and paranoid social misfit and loner, who was mainly driven by the need for attention, power and, most of all, credibility. He felt the urge to prove his intellectual superiority, in order to compensate his own feelings of inferiority and inadequacy. The UNSUB had also a self-conscious compulsiveness, meaning that he was obsessed with others underestimating him and appreciating his skills, being also convinced that society wronged him. In all likelihood, he spent the majority of his life with his mother, with whom he had a difficult relationship at best, and was not very successful with women. It was deemed probable that he had some relations with both Riverside College (where Cheri Jo Bates, a suspected Zodiac victim, was killed. Douglas was indeed fairly sure to attribute this murder to him) and Deer Lodge, Montana (the location of the prison he allegedly named during the Hartnell-Shepard attack. However, the validity of this claim is doubtful, as the prison name was merely deduced by a policeman who interrogated survivor Bryan Hartnell).
He may have spent some time in the military, probably in the Air Force or the Navy, where he was likely trained in codes. If this be the case, he would have been soon discharged out of medical reasons or no reasons given, because he couldn't cut in such a structured, disciplined environment long-term. He liked and was familiar with weapons, being probably a hunter, and had technical expertise, demonstrating skill with numbers and codes. The UNSUB also might have had a private work area, where he kept the materials he needed for his writings and press coverage of his crimes. He probably complained, with a confidant of some kind (most likely another loner), about law enforcement demonstrating incapacity in the Zodiac case.