The man who robbed the inside the on Dublin Boulevard on Tuesday afternoon is also believed to have robbed banks in Pleasanton and Lafayette, according to Lieutenant Herb Walters.
Walters said the same suspect is thought to have struck San Leandro.
But San Leandro Police Department spokesman Lieutenant Jeff Tudor said no one matching Dublin's description has robbed a bank inside the city limits.
Dublin police say the suspect is a white man in his mid-thirties, six feet tall, weighing approximately 200 pounds. He was wearing a black baseball hat, a black long sleeved shirt and blue jeans.
The Dublin suspect displayed no weapon and left with an unknown amount of cash, police said. His getaway vehicle may have been a white, 4-door, mid-90s, American-made car, but it is not known which way it went.
According to Walters, this is believed to be the eighth robbery committed by this same suspect in the last three weeks.
San Leandro police have reported two incidents involving bank robberies in recent weeks, but both of those cases resulted in arrests.
At the beginning of June San Leandro police with the arrest of a man suspected of robbing 11 banks throughout the Bay Area.
A few days later, an unarmed man dressed in a wig was caught on a surveillance camera for . But he was arrested after he got spooked and walked away without getting anything.