At 12:54 p.m. Saturday, police responded to a driveway on Dewitt Street in the Hill and found a man who had been shot in the chest.
The man, 28-year-old Gary Williams, was taken by ambulance to Yale New Haven Hospital, where he was pronounced dead at 1:44 p.m.
Detectives were on the scene collecting evidence and interviewing neighbors.
Police did not identify a suspect or suspects.
Police asked anyone with information about the crime to call 203-946-6304 or 203-946-6316.