Shatiek Johnson, convicted of fatally shooting New York City Police Department Housing Officer Gerard Carter in 1998, has died while serving a maximum prison sentence at Attica Correctional Facility, state correction officials confirmed. Johnson, 45, passed away on Tuesday after spending more than 25 years behind bars, according to the New York State Department of Corrections and Community Supervision.

The exact cause of Johnson’s death remains under investigation, with authorities conducting a toxicology report to determine the circumstances. Officials have not released additional details at this time.

Johnson was 17 when he shot Officer Carter at close range on July 26, 1998. Carter, 28, and his partner had been sitting in a marked police van while on patrol outside a Staten Island housing development when the incident occurred. Carter succumbed to his injuries several days later. At the time, he had served five years with the NYPD and left behind a 7-year-old son.

The case drew significant attention due to the fatal shooting of a young police officer engaged in community patrol duties. Johnson’s conviction resulted in a lengthy prison term, which he had been serving at Attica, one of the state’s maximum-security facilities.

Authorities continue to evaluate the circumstances surrounding Johnson’s death as the investigation proceeds.