A pedestrian shot at a passing vehicle, California Highway Patrol officers said.
The incident happened shortly before 4 p.m. Thursday near Interstate 805 and Bonita Road in Chula Vista.
After shooting at the passing vehicle on Bonita Road, the pedestrian then ran under the freeway and into a riverbed.
Chula Vista Police established a perimeter to look for the suspect.
A man showed up at a nearby hospital with a shooting wound to his stomach and leg.
Police are investigating the shooting and looking for connections between the shooter and victim.