FBI agents say the man entered the bank around 11:15 a.m. on Monday, April 29, and demanded cash from a teller and fled on foot with an undisclosed amount of money.
Officials have not said if he had a weapon or threatened to use one. No one was injured.
The man is described as a white male in his 20s with a goatee. He was wearing a white White Sox cap, a white hooded jacket with gray sleeves, and jeans.
Anyone who recognizes the man or has more information on the robbery should call (312) 421-6700.
