A federal warrant unsealed Thursday says agents found bomb-making materials at the apartment of the alleged gunman charged with fatally shooting seven people at a Fourth of July parade in suburban Chicago last year, the Chicago Tribune reported.Among the items found in the Highland Park-area home of Robert Crimo III days after the attack were commercial components used for explosions and a timer, according to the report.An affidavit attached to the warrant cited Crimo, 22, as telling FBI agents he mulled the possibility of …