Warren County Police say the 19-year-old was found leaning over the side of a bridge about four miles north of Indianola early Tuesday morning.
Backstrom was taken to Iowa Methodist Medical Center, where he died of his injuries.
Investigators say they are treating this case as a homicide, but the cause of Backstrom's death will not be determined until an autopsy is performed by the Polk County Medical Examiner's Office.
A statement issued by University President David Maxwell on Tuesday describes Backstrom as "the victim of an off-campus violent crime."
Backstrom was a sophomore at Drake University studying business. His friends said he loved playing video games and making people laugh.
Drake officials said the assault did not happen on campus and that other students should not be alarmed. The university will be offering grief counseling to faculty and students.
Anyone with information in this case is urged to call the Warren County Sheriff's Office at 515-961-1122.