USC stabbing kills psychology professor

LOS ANGELES — A graduate student arrested on suspicion of stabbing to deaththe professor who oversaw his work at the University of Southern California was being held on $1 million bail Saturday as their shocked colleagues began processing the news.

David Jonathan Brown, a 28-year-old brain and cognitive science student, was arrested in the Friday afternoon attack in the heart of the Los Angeles campus. His mentor, Bosco Tjan, was killed inside the Seeley G. Mudd building, where he runs an intensive lab that studies vision loss.

Brown, one of just five students who worked in the lab, was arrested without incident almost immediately afterward, police said, adding that the killing was targeted. In a biography page about the lab and the students involved in it, Brown’s is the only one without a detailed description or photograph.

Nathaniel Kwok, who recently finished working 18 months in the lab, said graduate students like Brown work in the lab 40 to 60 hours a week and develop their own projects that are required in order to graduate.