The shooting happened around 5 p.m. Saturday afternoon near the intersection of 20th Street and Pico Boulevard.
While fleeing, the woman flagged down a passing vehicle for help and jumped in a car with two people. According to Santa Monica Police, the suspect managed to catch up to the vehicle, run onto the sidewalk of the busy intersection, and shoot her multiple times. The vehicle driving the victim drove to Pico and Lincoln boulevards and called police after the shooting.
Officers arrested the man about an hour later after he fled the scene.
The unidentified woman is hospitalized, but is expected to be okay.
Authorities say she is not cooperating with their investigation.
The driver and passenger who stopped to help the victim were not injured.
CNS contributed to this report.