Sources tell NY1 that notorious killer David Berkowitz, known as the "Son of Sam," has been hospitalized in Albany.
They're not disclosing the reason, but Berkowitz remains in custody of the Shawangunk Correctional Facility.
The Post is reporting that the 64-year-old needed emergency heart surgery.
It's been 41 years since he terrorized the city — starting a killing spree in 1976 with a shooting in the Bronx.
It lasted a year and stretched into Brooklyn and Queens.
Thirteen people were shot and six were killed.
Berkowitz is serving six consecutive life sentences.