Agents call him the Citibank Bandit since a majority of the branches he hit were Citibanks.
Officials are circulating images of the man that were captured by bank surveillance cameras. Investigators say he is responsible for holding up 11 banks in and around the downtown Chicago area since February of 2009. The most recent was in January.
No injuries were reported in any of the robberies.
Anyone with information should call the FBI.