HBO has acquired U.S. television rights to director Marc Silver's 3 1/2 Minutes, a documentary about the shooting death of black teenager Jordan Davis and the subsequent trial of his killer, Michael Dunn. The docu premiered in the U.S. Documentary Competition at Sundance and will debut on HBO in late fall, preceded by a theatrical release. “I am grieved that these continuing stories are everyday matters swept away,” said Sheila Nevins, President of HBO Documentary Films.…