Police said the altercation started when Armstead, driving in his personal car, rammed a vehicle he'd been following on Route 211. Sources said his wife's lover was inside the other vehicle.
Wilkins got out of the vehicle and ran to a Buffalo Wild Wings parking lot, where police said Armstead shot and killed him.
“One guy jumps out, comes over here and starts shooting away,” Gary DeYoung told News 12 Westchester. “I was like, ‘Whoa.’ I called 911. By that time, there was two deceased on the ground here in the parking lot.”
Armstead's wife had arrived in another car and was not injured, police said.
"I hear pow, pow, pow, pow, pow,” another witness told CBS News. “Next thing I know, probably, I don't know how long afterwards, cops were all over this place. I mean, the smell of the gunpowder was so heavy.”
A Glock pistol and multiple spent shell casings were found at the scene of the shooting.
Armstead, of Port Jervis, N.Y., was reportedly supposed to be working a midnight shift in the Bronx at the time of the shooting.