Brothers of killed Florida doctoral students speak out

Prosecutors have revealed new evidence in the killing of a University of South Florida doctoral student, whose body was found last week on a Tampa Bay bridge, including a timeline of events surrounding the death of Zamil Limon and the disappearance of his close friend, postgraduate student Nahida Bristy. Limon’s roommate, Hisham Abugharbieh, has been charged with two counts of first-degree premeditated murder with a weapon in the deaths of the students. The brothers of both students tell CNN’s Isabel Rosales that they believe warning signs were missed.