The California Highway Patrol responded to the scene shortly before midnight on Sunday and found a female victim on the side of the road. Drivers heading north on the 15 Freeway had been calling 911 regarding the body.
Initially, officers thought the victim had been hit by a vehicle, but after further investigation, it was determined that the victim had injuries consistent with a homicide. Authorities have not released what type of injuries the victim suffered.
"She had suffered injuries that were consistent with foul play, and now she's considered a victim of a homicide," said Sgt. Joe Borja of the Riverside County Sheriff's Department.
Officials said the victim is a 26-year-old Hispanic woman. The victim's name has not been released pending notification of next of kin.
The investigation shut down all but one lane of the 15 North from Limonite Avenue to Cantu-Galleano Ranch Road, and traffic was backed up for several miles. All lanes were reopened by 8 a.m.
Anyone with information is urged to call the Riverside County Sheriff's Department at (951) 955-2777.