Todd Dickey (C), senior vice-president for administration at the University of Southern California, speaks as Los Angeles Police Department Commander William 'Bill' Scott (R) and LAPD Public Information Officer Commander Andrew J. Smith stand nearby, during a news conference in Los Angeles, California, July 28, 2014. Four people, two of them juveniles, have been arrested in the robbery and beating death last week of Chinese graduate student Ji Xinran, 24, near his off-campus apartment, Los Angeles Police officials said on Monday. [Photo/Agencies]