Investigators ultimately learned that Justin Su, then 20, was at Broward Community College in the early afternoon of Sept. 8, 2014. His vehicle was recorded leaving a campus parking lot. Detectives also learned that whoever struggled with the victim before she was bound, placed in a bathtub and stabbed between 20 and 27 times, left traces of DNA in three conspicuous places — a belt used to bind the victim, a knife used to strike her, and the broken sliding glass doorway that was the likely point of entry.