GRAND FORKS, N.D. (AP) - An Oklahoma man found dead in January in a vehicle parked on the University of North Dakota campus died of a drug overdose.

Police say an autopsy concluded that 19-year-old Braden Robertson, of Tulsa, Oklahoma, died from a mixture of methadone and an anxiety medicine.
 
Robertson was not a student at the university. WDAZ-TV (http://bit.ly/2ckWek6 ) reports that he was in Grand Forks visiting family.
 
No foul play is suspected in the death, but authorities are investigating the source of the drugs that killed Robertson.