In March, the FBI said it was seeking a bank robber in California who used wigs and facial hair disguises, calling him the Shaggy Bandit.

Another in Massachusetts was named the Faceless Bandit because he was completely masked. And in April, investigators sought a robber in Knoxville, Tennessee, whom they called the Edentulism Bandit because witnesses said he was missing several teeth.

The latest to appear on FBI “Wanted” posters is the Traveling Bandit, who authorities said Friday has robbed at least seven banks in six states in less than a month.

The Traveling Bandit has covered more than 3,200 miles in a string of robberies that started on Dec. 28 at a Capital Bank in Aventura, Florida, about 20 miles north of Miami. He progressed from there to holding up a bank in North Carolina, then two in Tennessee, and one each in Alabama and Illinois. His most recent one was on Thursday in Price, Utah.

The FBI said the robber, a man described as being between 40 and 50 years old, usually approaches the counter, presents a note demanding money, divulges that he has a weapon and then leaves on foot. The FBI said he might be driving a white Ford Explorer or Expedition.

Jim Marshall, a spokesman at the FBI’s field office in Miami, said no one has been injured in the robberies. He did not respond to questions about how much money the robber has garnered.

Robert J. Louden, a professor emeritus of criminal justice and homeland security at Georgian Court University in New Jersey, said Friday that the robber was staying one step ahead of law enforcement by covering so much territory.

“People that repeat things get caught, but he’s repeating things in such a way that each one is the first time,” he said.

With his robberies spread out among multiple states, it is more difficult to draw attention to him because there is not one concentrated news media market, he said.

Robert D. McCrie, a professor at John Jay College of Criminal Justice and a security specialist since 1970, said it also meant that the local law enforcement agencies investigating were more diffuse.

It was unknown whether officials were able to retain the notes the robber displayed, but if investigators did, they would be useful in finding physical evidence, such as DNA or fingerprints, and to study its verbiage and handwriting, Louden said.

The FBI released seven photos of the robber, including one in which he was wearing a shirt that said “Straight Outta Dallas.” Given the intensive use of surveillance cameras in public streets, traffic lights, tollbooths and other public spaces, how has the Traveling Bandit eluded capture?

McCrie said the answer was partly that the FBI had not made bank robberies a priority for decades. Facing other demands, such as addressing espionage and other issues related to the Cold War, the bureau scaled back its focus on bank robberies starting in 1980, he said.

“Routine bank robberies were not of significance,” he said. Marshall of the FBI did not immediately respond to a request for comment.

Still, “takeover” cases in which robbers vault over a counter and fire shots into a ceiling, terrorizing staff members and customers, will draw more law enforcement attention, McCrie said. He added that investigations into bank robberies have a high closure rate — upward of 70 percent — compared with other crimes.

Bank robbers generally garner a small sum per heist — usually less than $3,000, he said — in what is considered a “relatively safe” crime. Tellers are trained to turn over money quickly in an effort to hasten the robber’s exit.

“If there’s no real weapon shown, the risk for sanctions is lower” should the person be caught and prosecuted, he said, providing an example of an accused robber’s defense: “I never had a weapon. I may have acted tough, but the most dangerous thing I had was my Cross pencil.”

He added that bank robbers are “not usually evil people” compared with violent criminals. In prison, they are not regarded as “heroes,” but they are not at the bottom of the social strata either because they have credentials as courageous risk-takers, he said.

As for why authorities nickname the robbers, McCrie said it helps to cement an image in the minds of investigators and the public even if it feels faintly like it glorifies the criminals. Also, the FBI has long had a history of naming its investigations.

Louden speculated that the Traveling Bandit probably has a criminal record and that he might have a background as a courier or long-haul trucker.

“They’ll get him,” he said. “It’s almost impossible for somebody to stay out forever and not get caught.”