David Berkowitz Called Himself "Son of Sam" for a Very Strange Reason — Details on His Moniker

Believe it or not, serial killer David Berkowitz is a changed man. Back in the late 1970s, the "Son of Sam" was responsible for killing six people and wounding seven others. The murders stretched across New York City, causing a reign of terror that lasted an entire year. When he was arrested in August 1977, Berkowitz was initially deemed unfit to stand trial. He ultimately pleaded guilty to second-degree murder and received six consecutive life sentences.

While incarcerated, Berkowitz has completely turned himself around. He became a born-again Christian and minister, choosing to help his fellow inmates. Berkowitz also responds to letters with words of encouragement and told CBS News he takes a lot of pride in helping people. This has earned him a new nickname: "Son of Hope." Still, it's hard to shake a past as terrifying as Berkowitz's. Why did he call himself the "Son of Sam"? Here's what we know.

The first time police came across the "Son of Sam" nickname was in a letter the killer left at the crime scene of Valentina Suriani, 18, and 20-year-old Alesander Esau. He wrote, "Come and get me. Son of Sam." This was April 1977, and by June 3, a second letter was sent to Jimmy Breslin, a columnist for The Daily News, reported The New York Times.

The second note contained detailed references to 18-year-old Donna Laurie, who Berkowitz killed in July 1976. Like the first letter, he signed this one "Son of Sam" then added a few extra touches. Berkowitz also drew an X‐shaped mark with the biological signs for male and female. Above the X he sketched a cross and the initial S.

Berkowitz later told police that he called himself "Son of Sam" because of his neighbor's dog. He always heard it barking and could see into his neighbor's backyard where the dog was often outside, which enraged Berkowitz. The neighbor was a man named Sam Carr, and Berkowitz claimed his dog was possessed by a 6,000-year-old demon who told him to kill. This came after Berkowitz tried shooting the dog.

Two years after Berkowitz was arrested, he revealed that the possessed dog story was all a lie, per The New York Times. He chose that moment to tell the truth because at the time, the convicted killer was trying to lock down a multi-million dollar book deal/movie that was being negotiated by his former lawyers, the conservator of his estate, and the McGraw Hill Company.

Without a motive, Berkowitz was asked why he did it. "That, I really can't say," he replied. "Let's just say the whole thing was motiveless and senseless." This was in February 1979, and was also when Berkowitz revealed his urge to kill was gone. "Whatever it was has just worked out of me—I've mellowed," he shared. "I don't know what it is that started it and I don't know what it is that caused me to lose interest. I don't know."