They also dialed 911.
Officer Julie Beard said responding officers fired a bean bag at the 19-year-old woman Monday and took her into custody. She received minor injuries. Beard says the woman was armed with at least one knife.
Since the woman had left the backpack in an aisle of the Safeway store, police called for a bomb squad and a bomb-sniffing dog but the store was found to be safe.
Beard says the woman damaged unspecified property inside the store.
The officer said the woman was being held at a hospital, with a mental evaluation requested.