Authorities have arrested a Purdue University student in the killing of his roommate in their campus dorm room. Purdue Police Chief Lesley Wiete says Ji Min Sha, a 22-year-old cybersecurity major from Seoul, South Korea, was arrested on a preliminary murder charge in the killing of 20-year-old Varun Manish Chheda, a 20-year-old data science major from Indianapolis. The Tippecanoe County coroner says an autopsy determined that Chheda died of “multiple sharp-force traumatic injuries.” Wiete says Sha, who goes by the nickname “Jimmy,” called police at around 12:45 a.m. “alerting us to the death of his roommate” in their dorm room. She says investigators don't know why Chheda was killed, but she thinks it was “unprovoked and senseless.”