The Zodiac serial killer terrorized the San Francisco Bay area from December 1968 to October 1969 when the violent killings suddenly stopped. But the fear continued into another decade as the killer mailed a series of threatening letters and cards to several newspapers and police agencies. Considering the information in these letters and cards as diary entries, a unique profile of the killer soon emerged. The search was now on for a teacher well versed in astronomy not astrology and when found he would have an elaborate collection...he did.