The suspect, a man in his 30s, is accused of robbing three banks in the Loop since Sept. 16. He was apparently seen on surveillance changing clothes on public transportation after a robbery.

Authorities said it was the first incident in recent years in which they've observed a suspect changing clothes on public transportation.

The FBI’s Chicago Field Office is investigating a bank robbery that unfolded in the Loop on Tuesday afternoon and it may be just one of several robberies committed by a man who agents are calling the “Bare-Chested Bandit.

The FBI is asking for the public’s help in identifying a bank robbery suspect, known as the "Bare-Chested Bandit," who is believed to have carried out three heists in the Loop since mid-September.

The FBI’s Chicago Office is looking for a man they’ve dubbed the “Bare-Chested Bandit,” who has committed three bank robberies on the 100 of North Michigan in recent weeks.