Police are investigating a series of vandalism acts that occurred early Tuesday morning.
The San Luis Obispo Police Department began responding to several burglar alarm calls at the 3 a.m.
A total of 10 banks, mostly located in San Luis Obispo's downtown core and the Apple store had their windows broken.
Police found small metal balls at several of the locations. Officials say these are commonly used with sling-slots.
Sgt. Kurt Hixenbaugh said they received the last report Tuesday afternoon.
"When we started taking the fourth one, that's when I began thinking, 'Okay, what the heck's going on here? It's got a pattern.' The number just kept climbing," Hixenbaugh said.
Officials cannot say if this is the work of an individual or of a team.
Some of these windows are very expensive to replace. The Apple store's window is valued at $20,000.