DENVER -- The FBI is asking for the public's help in finding a serial bank robber they have dubbed the Shaggy Bandit, who is believed to be responsible for at least 12 bank robberies in Colorado and Arizona.

The most recent robbery happened at the First Bank on South Buckley Road in Aurora, said Special Agent Kathy Wright.

The robberies have happened at banks in Longmont, Boulder, Westminster, Arvada, Denver and Aurora. The first robbery happened on June 24, Wright said.

"He seems to prefer banks inside grocery stores," Wright said. The robber will demand money from the teller and use a black and blue backpack to hold the money, she said.

"Generally, he steals the money and leaves without drawing any attention from other customers or bank employees," Wright said.

Investigators said they believe the man has an accomplice in a get-away car waiting outside the bank. However, the FBI does not have a description of that car.

Wright said the man has been called the Shaggy Bandit because he resembles Shaggy from "Scooby Doo."

The Shaggy Bandit is assumed to be armed and dangerous, Wright said.

Anyone with information about his whereabouts is asked to call the FBI Rocky Mountain Safe Streets Task Force at 303-629-7171, or, CRIMESTOPPERS at 720-913-STOP (7867).