Officials said he initially targeted banks along the I-55 corridor near St. Louis, but then expanded his operation to West Virginia, Maryland and Tennessee. He's struck three banks in the last 30 days, FBI agents say.
"The more often a bank robber commits a crime or commits a bank robbery, chances are, they'll get caught because they leave behind more clues," Rebecca Wu, FBI, St. Louis Field Office, said.
The FBI put up billboard along the I-55 corridor with the suspect's picture.
The I-55 bandit is white, in his 20s and has strawberry blond hair. He wears dark glasses and a hat during the bank robberies. He implies he's armed and then hands a note to bank tellers demanding money.