The first incidents were reported on December 30 and 31, and another string of incidents occurred on January 3.
Andriese said someone is throwing rocks or shooting a BB gun at windshields and windows of parked vehicles at night.
Police have said there are some 30 cases of vandalism of vehicles throughout the city at this time.
Additionally, in an incident that police are unsure is related, someone threw a rock into the windshield of Patterson Fire Truck No. 2 near the corner of Sperry Avenue and Third Street around 9 p.m. Tuesday, Jan. 14.
Deputies are looking for a man in his early 20s, measuring in at roughly 5 feet 10 inches tall and 150 pounds. He was last seen wearing a black hooded sweatshirt over a red t-shirt.
Anyone with information on either of these incidents is asked to call Detective Michael Andriese at 209-892-5071.
Nick Rappley can be reached at 209-568-9975 or firstname.lastname@example.org.