BOSTON - A Boston man is accused of firing upon at least 21 of the city's police officers during a night of violence and looting that started late on Sunday. John Boampong, 37, of Dorchester is being held without bail following a Wednesday hearing in Boston Municipal Court, during which Suffolk County prosecutors presented evidence to prove that he presented a danger to the public. He was arraigned on 21 counts of armed assault with intent to murder in connection with the shooting that happened on Providence Street in the early hours of Monday morning. Prosecutors accused Boampong of firing...