Officer Brian Moore followed his father into the New York Police Department, rose to the ranks of an elite plainclothes unit tasked with confronting the city’s most dangerous street crime and died on Monday, two days after a gunman opened fire on him in Queens.

At the time that Officer Moore, 25, was shot on Saturday evening, he was still young enough to be living in the Long Island home of his father, Raymond. Yet he was seasoned enough in the job he had been drawn to since childhood to have earned accolades from superiors and departmental medals for “meritorious” police work. He had made over 150 arrests since joining the department in July 2010.

“In his very brief career, he already proved himself to be an exceptional young officer,” the police commissioner, William J. Bratton, said in announcing Officer Moore’s death, outside Jamaica Hospital Medical Center on Monday.

“I did not know this officer in person in life,” Mr. Bratton added. “I’ve only come to know him in death.”