SPRINGDALE - A suspected bank robber was trapped inside the building's security door system as she tried to make her getaway Monday afternoon.

"The system appeared to work," said Police Lt. Rick Neumann, who responded to the bank with another officer and arrested the woman.

Police charged Donna I. Garrison, 46, of Hamilton, with aggravated robbery.

The robber entered the bank about 3:50 p.m., pulled a knit cap with eye holes over her face, approached a teller and demanded money, Lt. Newmann said. She said she had a gun, but no weapon was shown.

After receiving some cash, the woman entered the two-door security system, Lt. Neumann said. A teller activated the locking mechanism, trapping her between the two doors. The robber then pulled what appeared to a semiautomatic handgun from a handbag and began shooting toward the floor at the outer door.

"We think she was trying to shoot the locking mechanism," the lieutenant said.

It turned out the gun was a plastic BB gun. When officers arrived and arrested the woman, they found about 20 BB pellets on the floor.