The professor who taught him, Lucinda Roy, said she spoke repeatedly to the university authorities about him, adding she was so concerned by what she found that she decided to take him out of the classroom for one-to-one tutoring.

BBC: NEWS | Americas | Loner filled with anger and spite

She said she later contacted campus police because she was "so concerned" about what happened during her last meeting with him, but she declined to detail what bothered her.

CNN: STORY HIGHLIGHTS