The shooting happened about 8:10 p.m. on Grace Street in the Cedar Hill neighborhood, they said.
Medics treated the gravely wounded 24-year-old man and took him to Yale-New Haven Hospital, where he was pronounced dead. Police said he lived in New Haven.
Major Crimes detectives continue to investigate the homicide. Anyone with information is asked to call the New Haven Police Department at 203-946-6304. Callers may remain anonymous.