Prosecutors: USF students had explosive materials, instructions. TAMPA - Pipes stuffed with fertilizer, Karo syrup and kitty litter. Bullets and fuses. A laptop with Internet searches about martyrdom, Hamas and Qassam rockets. Video instructions for turning a child's toy into a detonator. After weeks of silence, the U.S. Attorney's Office opened up about its case against two University of South Florida engineering students facing explosives charges, implying that Youssef Megahed and Ahmed Mohamed had something sinister in mind when they left Tampa in early August and headed north. Despite the grim implications of what the government presented, prosecutors said they...