The accident happened at the intersection of 17th Street East and Avenue R just before 4:30 p.m. It's unclear what caused the crash, but authorities say the deputy's vehicle did not have lights and sirens on.
Overcome by grief and shock, the family of 20-year-old Sara Paynter gathered at the accident scene. Her body, covered by a sheet, was too much for her father to bare.
"It's not OK, my daughter's dead," her father shouted at investigators. "This is not OK."
Investigators say a Ford Explorer was traveling northbound on 17th Street East, and the deputy was traveling eastbound on Avenue R when the two vehicles collided. Paynter and her boyfriend, 31-year-old Robert Delgadillo, who were in the backseat of the Explorer, were ejected from the SUV.
Authorities say they do not know yet if the two victims were wearing seatbelts. They were declared dead at the scene.
The driver of the Explorer and front seat passenger were not hurt. The sheriff's deputy had minor injuries.
Investigators say they have conflicting witness statements on how fast the deputy was going and if the Explorer had stopped at the stop sign. Painter's father says deputies often speed down Avenue R, and he doesn't believe the driver of the Explorer was at fault.
The California Highway Patrol is handling the crash investigation.