At about 1 p.m., police were dispatched to the 800 block of Cherry Avenue on a report that a carjacking had just occurred, the San Bruno Police Department said.
Police said that the suspect, later identified as 30-year-old Castro Valley resident Jaime Campos, had shoved the victim away from her car as she was unlocking the door.
He then hopped into the vehicle and fled east on San Bruno Avenue toward El Camino Real, according to police.
While traveling south in the 1300 block of El Camino Real, officers conducted a traffic stop and arrested Campos.
He was booked into San Mateo County Jail and is being held on multiple charges, including carjacking.