In the early 1980s the radical group MOVE settled into a rowhouse in a predominantly African-American neighborhood of west Philadelphia, beginning years of confrontations with neighbors and police over its anti-establishment ways and militant stance against all social and political institutions. On May 13, 1985, following a period of increased MOVE activity and threats by neighbors to take matters into their own hands, the city moved from bureaucratic involvement to violent intervention. Police bullhorned arrest warrants, hosed down the rowhouse, sprayed tear gas through its walls, and...