It happened in Farmingville at about 10:15 p.m. on Wednesday, Dec. 7, the Suffolk County Police Department reported.
Police said a woman was driving a 2007 BMW west on the Long Island Expressway between Exits 64 and 63 with a male and female passenger in the vehicle when she was involved in the incident with a male driver who was traveling in the same direction.
The two vehicles exited the LIE at Exit 63 and stopped at a traffic light on Express Drive North at North Ocean Avenue, police said.
The suspect walked up to the BMW and tried to open the driver's door, which was locked, authorities reported.
SCPD said the man reached into the open back window to grab the driver, and a male passenger in the back seat grabbed the suspect's arm.
During a struggle, the suspect cut the passenger's throat, causing a four-inch laceration, police reported.
The driver drove through the red light to escape the assault and went to City MD Office, which is located at 2280A North Ocean Ave., authorities said.
The suspect returned to his car and fled the scene, traveling north on North Ocean Avenue, SCPD reported.
Police said the passenger was treated for non-life-threatening injuries at Stony Brook University Hospital, police said.
Police said that the suspect is a Hispanic man who appeared to be in his mid-30s to 40s, with a medium build, brown eyes, and brown curly hair.
He was wearing a winter hat and a light blue t-shirt, according to the report.
His vehicle was described as a royal blue four-door sedan that may have been a Mazda 3 or 6, with yellow New York plates, authorities said. There may have been a female passenger in the car, police said.
Detectives asked anyone with information about the case to call police at 631-854-8652 or Crime Stoppers at 1-800-220-TIPS.
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