Police say on September 1, a masked man walked into the Malvern Federal Savings Bank in Berwyn using the rear door.
When he reached the main lobby area, police say he was met by an armed security guard who had just walked in the front door.
The suspect quickly walked by the guard and out the front door. He then fled to the back lot area and left in a red SUV, possibly a red Nissan Pathfinder.
The vehicle drove south on Main Street before disappearing.
The suspect is described as a white male in his 50's, 5'6" to 5'8", heavy build, wearing a hat, sunglasses and a white towel over his face. He was also carrying a black soft briefcase.
Police believe he may be the same man who robbed the Citizen's Bank in Easttown on August 7, 2010.
Anyone with information is asked to call Easttown Township Police at 610-647-1440.