The victim, whose name the police did not release, was shot six times — in the arm, hand and torso. He was listed in stable condition and expected to survive, Chief Benefico said. The car the victim was riding in was shown in news agency photos and videos parked outside the hospital, its windshield pocked with bullet holes.

Chief Benefico said that officials had not identified any possible motives, though the New York police commissioner, William J. Bratton, said alcohol might have played a role.

“As of right now it seems to be completely random,” Chief Benefico said. “We have nothing to link either party to each other — no road rage, nothing right now. We are looking into that, but we have no link that connects the two of them.”

After the shooting, the police said, Officer Cronin drove off. He was stopped a short distance away in New Rochelle by a Pelham police officer. As the officer approached, he noticed Officer Cronin pointing a gun out of the car window, the Pelham police said in a statement. He was ordered several times to drop the gun and eventually did, the statement said.

Image Brendan Cronin, 27.

Officer Cronin, who refused to take a blood-alcohol test, was arrested and charged with first degree assault. He was expected to be arraigned on Wednesday evening.