An apparent altercation on Route 211 between two motorists preceded a murder-suicide that occurred outside a restaurant in Walkill earlier this week, the Wallkill police chief said Thursday night.

The fatal incident that occurred outside a Buffalo Wild Wings late Sunday night involved Sean Armstead, a 36-year-old New York City police officer from Port Jervis, and Edward Wilkins, a 20-year-old Wurtsboro resident who worked as a security guard with Resorts World Casino, police said.

According to Police Chief Robert C. Hertman, both men were off-duty and driving west in separate vehicles alone on Route 211 near Tower Drive around 10:30 p.m. Sunday, when Armstead’s vehicle struck Wilkins’ vehicle.

Following a brief altercation, Armstead fired a pistol at Wilkins as he fled on foot and struck him multiple times before taking his own life with gunfire, police said.

The pistol recovered at the scene was determined to be Armstead’s police service weapon, according to Hertman. He said an investigation into the incident determined Armstead and Wilkins were known to each other prior to the shooting.

Police found both men deceased in the parking lot.

The ongoing investigation is being conducted by the state attorney general’s office and the Wallkill Police Department.