his name was eddie seda.year-old high school dropout, unemployed who was still living at home with his mother and younger sister. >> on days he seemed religious and quiet and strange and other days he seemed aggressive and scary. >> at headquarters police asked seda to provide a written statement describing what happened inside his apartment. seda complied and when finished he signed it with an odd symbol next to his name. >> and the detective who did it looks at it and says what's this? >> and he said that that was a symbol for god and god's love or something. >> an alert police officer asked hostage negotiator joseph herbert to have a look. herbert knew immediately what he was looking at. >> the statement out of my mouth was, as sure as i'm standing here this is the zodiac killer. >> to prove their suspicions, police turned to forensic science. first seda was fingerprinted. his prints were then compared with the print left on the letter in central park. it was a match. next, handwriting experts compared the