It happened on Tuesday afternoon in the Illinois Medical District at 2111 West Roosevelt Road.
A suspect was taken into custody, the FBI confirmed.
ABC7 Chicago captured the moment a man with a ponytail, wearing a white T-shirt was being escorted in handcuffs out of the building by Chicago police officers.
The FBI said there were no injuries related to the incident.
No other information was immediately made available. CPD has not commented on the arrest.
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