The pepper spray attacks have happened in Benicia, Petaluma and as of Sunday, Santa Rosa at Grog Shop Liquor.
Police don't know if the attacks are related, but the cases are very similar. In each case, the thief gets what he's after but sprays his victims anyway.
"They're really nice, it's a family-operated business," said Grog Shop customer Jeremy Johnson. "They're just really amazing. It really hurts."
The armed thief took a bag full of cash from Grog Shop Liquor and then proceeded to spray the cashier and customers.
"The fact that someone just came in and just sprays her for no reason, I mean he got what he wanted, he got the money," an employee said.
Last week, similar attacks were reported at a Benicia mini market and a Petaluma hair salon. Police in all three cities are sharing information and ask that anyone who knows something about the attacks to please give them a call.