An off-duty New Jersey police officer was found shot to death inside his personal car Monday, which was parked at an abandoned movie theater complex, officials said.

The officer, a member of the Sayreville Police Department, was discovered dead around 7:15 a.m. after authorities found his vehicle near the Amboy Cinema just off the Garden State Parkway, which has been out of business for a decade.

The officer was not on duty at the time, but may have been investigating a report of a suspicious person when he was ambushed, NBC New York reported, citing unnamed sources. The Star-Ledger/NJ.com reported it was unclear why he was at the complex.

The Sayreville Police Department and Middlesex County Prosecutor’s Office could not immediately be reached for comment.

They are still investigating the homicide.