NEW YORK (AP) – A policeman patrolling with three partners in an unmarked car was shot and wounded by a motorist early Saturday morning, and the husband of another officer was detained for questioning in the crime.

The incident unfolded just after 4 a.m. in Brooklyn’s Park Slope section and sparked a hail of gunfire that littered the street with spent shell casings.

A four-year member of the force, Andrew Suarez, was struck in the back by the initial shot, but is expected to make a full recovery.

The shooter and a passenger escaped. But two men were later detained at a home about a block away. Police Commissioner Raymond Kelly said one of the two suspects was the husband of a veteran policewoman.

Police said they later recovered a loaded 9mm handgun in a yard on the same block where the men were arrested.

Investigators said the gunplay began when Suarez and three fellow plainclothes officers on a routine anti-crime watch pulled their car over to get a closer look at a vehicle driving behind them. That car then slowed alongside the officers.

Mr. Kelly said the driver leaned across the body of a male passenger, shouted “You got a beef?” and fired a shot at Suarez, who was driving. The bullet traveled underneath his bulletproof vest, through his back and lodged in his neck. A second shot may have also been fired, Mr. Kelly said.

The three other police officers returned fire, blasting at least 13 shots before the car sped away.

The case took a surprising twist a short time later when police stopped a vehicle matching the description of the one involved in the shooting. At the time, a female police officer was behind the wheel, Mr. Kelly said.

Just what the officer was doing with the car, a mile and a half from the crime scene, was unclear, but investigators do not believe she was present for the shooting, Kelly said.

Police raided her home and detained two men, including her husband. Charges were not immediately filed Saturday, and authorities said they were still trying to sort things out.

“We never want to jump to conclusions,” Mayor Bloomberg said in a news conference Saturday morning at the hospital where Mr. Suarez was being treated.

Authorities did not identify the suspects or the female officer, who they said had been with the force for 13 years.

Investigators had not yet recovered the weapon believed to have fired the shot at Mr. Suarez, Mr. Kelly said.

Mr. Suarez was appointed to the force in 2003 and is assigned to the 78th precinct.

Mr. Bloomberg met with Mr. Suarez at the hospital and said he was in good spirits.

“We joked and we laughed,” Mr. Bloomberg said. “We’re just lucky this wasn’t an awful lot worse.”

Mr. Suarez was the first city police officer shot this year, and the third wounded by gunfire since October.

“Let us pray that it’s the last,” Mr. Bloomberg said