At about 1:43 p.m., a man wearing a hooded sweatshirt and a mask depicting the "Iron Man" comic book and movie character walked into the Citibank branch located on the 500 block of Camino de Estrella.
The suspect displayed a silver handgun, according to the Orange County Sheriff's Dept. He took an undisclosed amount of cash and was last seen fleeing in a white Toyota Tundra pickup truck.
Authorities say the suspect was in and out of the bank within 40 seconds. He's believed to have been acting alone.
The suspect was described as a white man standing 6 feet tall and wearing a dark hooded sweatshirt.
Anyone with information related to the case should call the Orange County Sheriff Tip Line at (866) TIP-OCSD or the FBI Orange County office at (714) 939-8699.