The bureau released a surveillance image of him at the Chase Bank at 5352 North Elston Avenue on Chicago's Northwest Side.
Investigators said he robbed the bank just before 6 p.m. Wednesday. No one was hurt.
The North Center Bandit is thought to be behind at least four other robberies, which occurred at:
-The PNC Bank branch at 4201 North Lincoln Avenue at 2:24 p.m. on Aug 21.
-The Chase Bank branch at 3335 North Ashland Ave at 4:02 p.m. on Aug. 27 and at 4:09 p.m. on Oct. 20.
-The Chase Bank branch at 3339 West Belmont Avenue at 4:06 p.m. on Sept. 25.
The suspect is described as a Caucasian man in his late 20s or early 30s with brown hair. He is between 5 ft. 11 in. and 6 ft. 2 in. tall and weighs around 180-200 pounds.
Sometimes the brim of his cap obscures his face. But on Wednesday, he wore his hat backward and a surveillance camera captured a clear image of his face.
Anyone with information regarding these robberies should contact the FBI at 312-421-6700.