David Berkowitz (search), the "Son of Sam" killer who terrorized New York City in the summer of 1977, was denied parole for a second time, officials said Friday.

Berkowitz is serving six consecutive 25-years-to-life sentences at a maximum-security prison in Fallsburg. Though he did not request parole, the issue is automatically considered every two years.

The state Parole Board made its decision Thursday. The grounds for the denial were not disclosed.

Berkowitz, a former postal worker, killed six people and wounded seven others in a shooting spree that began in 1976. It wasn't until the fourth attack in January 1977 that police noticed a pattern. Authorities said he targeted teen girls with long, dark hair and young couples parked in lovers' lanes.

His nickname came from a note he left at one crime scene that read: "I am a monster. I am the Son of Sam."

Berkowitz told police after his 1977 arrest that he was following the demonic orders of his neighbor's dog.

Berkowitz, 51, has since said that he became a Christian and has a Web site filled with Christian-themed messages of remorse. In a 2002 letter to Gov. George Pataki (search), Berkowitz stated he had no interest in parole, saying "I can give you no good reason why I should even be considered."