Sgt. Stephanie Selinske of the Costa Mesa police told The Orange County Register that Tamera Grant ran inside the DMV office Saturday and refused to come out for two hours.
Grant came out 7:30 p.m., as a bomb squad arrived, and tried to drive off, police said.
Police opened the car's door and a K-9 dog moved in on her. She was taken to the hospital and treated for minor bite wounds.
Grant later told police she was trying to mail a letter, Selinske said.