A revised version of this article can be found here.

A police officer fatally shot an unarmed 22-year-old man early Thursday morning during a traffic stop on the side of a highway in Queens, the police said.

The shooting occurred at 5:15 a.m. on the Grand Central Parkway near La Guardia Airport after the police pulled over the driver, who had been driving erratically and twice cut between two police vehicles from the Emergency Services Unit, the police said.

The man, whose age was initially listed as 20, was shot in the abdomen; he was pronounced dead at New York Hospital Queens, the police said. The police did not identify the man, but said he lived in LeFrak City, a rental complex in Corona, Queens.

The two passengers in the car, which was traveling eastbound and had recently left a Queens nightclub called the Ice Lounge, included a woman who worked as bartender at the club and a female off-duty police officer. The police said the off-duty officer had been asleep in the back seat and did not witness the shooting.

No one else was injured, the police said. A small power drill was found in the car, the police said, and no gun was recovered.

The manager of the lounge, Moez Abouelnaga, said the victim occasionally worked there preparing hookahs and gave his name as Noel Polanco. But he said Mr. Polanco was not on duty on Wednesday night.

“He came to pick up the bartender,” he said, adding that this was a weekly routine for Mr. Polanco and the bartender, Diane Deferrari, 36, who lived in the same apartment complex. She needed help getting home after work because she had been charged with drunken driving, Mr. Abouelnaga said.

“Anytime you need something, he would never say no,” he said.

Mr. Polanco, who lived with his mother, also worked another job as a detailer at a local Honda dealership on Northern Boulevard. Six weeks ago, he also became a customer, buying a black Honda there. It would be the car he was killed in.

“He was a hardworking guy — an active duty military guy — disciplined and polite,” said Brian Benstock, the general manager at Paragon Honda. “He did what he was supposed to do.”

Those who knew him spoke of his desire to work hard and play by the rules. “This kid, Noel, he would never do something stupid,” said Nelson de la Rosa, 32, a club promoter who worked with Mr. Polanco at the Ice Lounge. “Check the record — he’s an Army reservist.” The Army did not immediately respond to an inquiry.

Early on Thursday morning, Mr. Polanco came to the club around 3 a.m. as he usually did to hang out before picking up Ms. Deferrari and driving home, Mr. de la Rosa said.

After finishing with work around 5 a.m., the police said, Ms. Deferrari and Mr. Polanco left the club along with her friend, an off-duty police officer. Mr. de la Rosa said the officer, Vanessa Rodriguez, also lives in LeFrak city.

Less than fifteen minutes later, they had an encounter with the police traveling in an unmarked truck and an unmarked van. The vehicles carried uniformed officers from the apprehension team of the Emergency Service Unit, who were traveling from the Bronx to Brooklyn to execute a warrant, the police said.

With sirens flashing, the police vehicles sandwiched the Honda, and slowed, causing the driver to stop, the police said.

Two officers in the front police vehicle — a sergeant and a detective — approached the car, a Honda. The detective was on the passenger side, where the window was open, the police said. Ms. Deferrari, who was seated there, later told the police that she had heard the officers tell those inside the car to show their hands.

The police said there were reports of movement inside the car but they would not elaborate.

The detective, Hassan Hamdy, a 39-year-old officer who joined the force in 1998, fired a single shot that hit the driver, the police said. The officer had no prior shooting incidents.

Ms. Deferrari told the police that she had served drinks to Mr. Polanco at the club, which is on Broadway in Astoria.

The police did not say how many drinks the driver had consumed nor whether he had made any movement inside the car after the stop.

Detective Hamdy had worked his way up to the elite Emergency Service Unit, where he was assigned to a team of highly trained officers who specialize in apprehending violent felony suspects. He has worked in the unit for nearly seven years, the police said.