The man has been identified as 44-year-old Anthony Wayne Ransom, who remains at large.
He has been charged with the robbery of the Citizens Bank branch at 2516 Welsh Road on July 12th.
The FBI says Ransom gave a threatening demand note to the teller then, after obtaining an undisclosed amount of cash, fled the bank on foot.
Ransom is described as a black man, about 6'3" tall and weighing 250 pounds. The FBI said he has, in the past, worn a thick beard.
Ransom is also being sought for escaping from the custody of a federal half-way house in Philadelphia on June 26, 2010. Ransom left the halfway house on that day to go to work, and never returned to the halfway house or to his place of employment in Willow Grove, PA.
Ransom may be frequenting the Jenkintown and Abington areas, the FBI said.
Anyone with information is asked to call the FBI at 215-418-4000.