Authorities were searching on Thursday for a person they say shot and injured a New York state trooper on the Southern State Parkway on Long Island overnight.

The shooting happened at around 11:45 p.m. on Oct. 30 on the westbound side of the parkway near Exit 17 in West Hempstead Nassau County, according to New York State Police. Police said the shooter, who is believed to be a male, sped away from the scene in a black sedan — possibly a Dodge Charger — with a temporary New Jersey license plate numbered 997636T.

The vehicle was described as having “custom matte gray dual exhaust tips.”

State Police officials said at a press conference on Thursday morning that 27-year-old trooper Thomas Mascia had pulled up to help someone he thought was a stranded driver.

“Unfortunately, Trooper Mascia’s good intentions were met with unexpected gunshots directed at him from a coward who, without any provocation or good shot or good cause, began to shoot at him,” said Major Stephen Udice.

Mascia heard several pops, and then realized he was struck in the leg, authorities said. He then retreated to his patrol car, tended to his own wounds using a first aid kit and called for backup, Udice said.

Mascia did not get a chance to return fire, because the shooter immediately fled the scene, according to Udice.

Other troopers began to arrive and one of them transported Mascia to the Nassau County Medical Center for treatment, where he was reported to be in stable condition, police said.

New York State Police are asking for the public’s assistance in locating the vehicle and alleged shooter. They say anyone who saw a vehicle that fits the description in that area on Wednesday night can call the department at 631-756-3300. Anyone who provides information that leads to an arrest and conviction could receive a $5,000 reward from the the Suffolk County Crime Stoppers.

“Someone who is willing to fire a gun at a law enforcement officer is most certainly a dangerous individual, so in order to ensure the safety of the public, we would like to get that person in custody as soon as possible,” New York State Police Superintendent Steven James said.

Police told Gothamist that while the shooter is believed to be male, they couldn’t definitively confirm the person’s gender.

“We are sickened by the actions of this cowardly individual who thought nothing of shooting a Trooper who was simply doing his job,” the Police Benevolent Association of the New York State Troopers said in a statement on Thursday. “This perpetrator must be brought to swift justice. We thank the medical providers who are providing our brother with the care he needs, and we will support him as he makes what we hope is a speedy recovery.”

This story has been updated with more information from New York State Police about the shooting that injured a state trooper.