A surveillance camera at the MB Financial Bank at Halsted and Madison captured an image of the bandit as he tried to rob it in January.
Authorities say the suspect has hit two other MB Financial Banks on the North Side since December. In each incident he threatens to hurt the teller if his demands weren't met within 10 seconds. No one has been injured.
The suspect is between 24 and 36 years old, stands between 5-feet-7 and 6-feet tall, with pock marks on his face.
In 2006 another robber used a similar tactic. He was arrested and charged.