A male student of a top private university in Seoul is under police investigation on suspicion of sexually assaulting a total of 19 female schoolmates, school officials said Wednesday. The Seongbuk Police Station is investigating the male student of Korea University, whose identity has been withheld, for allegedly taking sexually explicit photos and videos of the women while they were asleep after drinking alcohol on campus grounds between May 2011 and March 2013, they said.