Not long after finishing a performance in Brooklyn, Lionel Pickens, a local rapper better known by his stage name Chinx, headed back to Queens with a friend. It was early Sunday and they drove to a hookah bar, but finding it closed, they decided to call it a night.

As Mr. Pickens idled at a red light in his silver, late-model Porsche on Queens Boulevard, another car pulled alongside. Without warning, shots began piercing through the half-open driver’s side window at close enough range that detectives later found a 9-millimeter shell casing inside the Porsche on the front seat.

Mr. Pickens, 31, was struck at least eight times — and possibly many more — before he managed to pull his car to the curb in front of a Dunkin’ Donuts as the other car sped away. Taken to Jamaica Hospital Medical Center, Mr. Pickens died. His friend, Antar Alziadi, 27, survived. The police said he was in stable condition Sunday afternoon with two bullet wounds to the back and a punctured lung.

By late Sunday, no arrests had been made, the police said, and detectives were still searching for video of the killing and the car used by the assailants.