The FBI is seeking the public's help in catching a serial bank robber dubbed the I-55 Bandit, who is suspected in 10 robberies across five states.

Authorities believe the man has struck banks in Missouri, Illinois, Maryland, West Virginia and now Tennessee, where he is suspected of robbing three banks in the last month. The man also attempted to rob at least two other banks, according to authorities.

"We have seen cases, it's more rare, when the bank robber goes across the country and different states," FBI spokeswoman Rebecca Wu told ABC News.

In each case the man has been caught on surveillance cameras walking into the bank calmly, usually sporting a hat and a pair of dark sunglasses. He then implies that he is armed and slips the teller a note demanding money.

"Whatever the instructions may be by the bad guy, they're instructed to follow," former FBI agent and ABC News consultant Brad Garrett said.

The FBI did not disclose the amount of money taken in the crimes and no one has been hurt in the robberies.

The I-55 Bandit is described as a white male in his early to mid 20s, about 6'3? inches tall with brown or strawberry blond hair.

Investigators are hoping the public will help identify him by placing digital billboards with his surveillance camera picture across the country. It's a move investigators say has worked for them in the past.

"Billboards are extremely effective because it gives you a broad audience view of your bad guy," Garrett said.

The FBI dubbed him the I-55 Bandit because he initially targeted banks along the I-55 corridor near St. Louis, Mo. The FBI believes it's only a matter of time until he's caught.

"The more often a bank robber commits a crime or commits a bank robbery, chances are, he'll get caught because they leave behind more clues," Wu said.