The US Justice Department is launching a civil investigation into how sexual assault cases are handled in a Montana college town, a federal prosecutor said. Thomas E. Perez of the department\'s Civil Rights Division said investigators would review reports of 80 rapes that occurred in Missoula during the past three years, The Missoulian reported Wednesday. The federal review follows a University of Montana investigation that began in December with allegations that two students were gang-raped, possibly after being drugged by several male students. A former Montana Supreme Court justice hired to look into the matter concluded that the university has a problem with sexual assault both on and off campus. In February the university notified a Saudi exchange student that he\'d been accused of rape but the student fled the country before his victim filed a report with police. The department review will examine all Missoula rape reports for the last three years, not just those involving college students.