Who is the Son of Sam?
The killer could be a laid-off policeman. This theory is favored because the killer has a knowledge of guns, fires with accuracy from a combat stance, has knowledge of neighborhoods, and in one letter referred to the NCIC.
The killer could be a freelance journalist. In his letters Son of Sam writes with clarity and follows punctuation rules, including the use of a semicolon. The possibility that he may be a freelancer would explain why he hasn’t been turned in by coworkers noticing similarities to the police sketches. The police believe a journalist could also freely return to the scene of the crime.
The killer is a taxi driver – This theory explains his knowledge of neighborhoods and escape routes in the city. It would also provide the killer with a getaway vehicle that might not be noticed and with an occupation that would provide both the anonymity and the flexible schedule required to plan the eight attacks.
Excerpt from Howard Blum Aug 4, 1977 New York Times