An apparent mistake made by New Jersey State Police as they tried to track down the source of a 911 hangup lead to a brief exchange of gunfire with a homeowner just before 11:30 p.m. Friday night, when officers began knocking on doors at the wrong residence. 

The state Attorney General’s office said in a statement Saturday that a preliminary investigation indicated two troopers went to a house on the 200 block of Centerton Road in Upper Deerfield Township. The two were responding to a report that a emergency call was made from a cell phone in that home, Philly.com reported.

The officers approached the rural home of Gerald Sykes, 76, and his wife, according to the report. After not getting an answer at the front door, the officers reportedly went to the back of the home, knocking on a sliding glass door window, shining flashlights into the home and yelling that they were responding to a 911 call.

"At that time, there was an exchange of gunfire through the sliding glass door in which one of the troopers fired four rounds from his service 9mm handgun and Gerald Sykes fired a single round from a shotgun," the statement said.

Investigators are still trying to determine who shot first. Sykes was reportedly shot multiple times and was airlifted to Cooper University Hospital, where he remains in stable but critical condition.

The two officers were also injured, though the report did not indicate how. Both were later released from the hospital.

Authorities continue to investigate the circumstances of the incident, according to the statement.