Boston police are investigating an apparent homicide in Dorchester early Monday morning. Officers responded to the Edson Street area after receiving a report of a gunshot around 1:43 a.m. and found a man, believed to be in his late 20s, suffering from a gunshot wound outside 36 Whitman St., police said. The man was taken to Boston Medical Center, where he was later pronounced dead, police said. Police said there were no new details on the killing late Monday night. The name of the shooting victim has not been released.Sarah N. Mattero can be reached at email@example.com.