A former University of South Florida student has been charged with killing his roommate and the roommate’s girlfriend – two doctoral students from Bangladesh who disappeared earlier this month, authorities said Saturday. Hisham Abugharbieh, 26, is facing two counts of premeditated murder in the first degree with a weapon in the deaths of Zamil Limon and Nahida Bristy, students at USF, according to the Hillsborough County Sheriff’s Office. He made an initial court appearance Saturday in Tampa,...