Continued from page 1

“I am totally not a fan of that,” said Mr. May, who has spent 11 years tracking bank robbers. “[Those tellers] are scared to death. They are worried that person is going to come back again and kill them.”

Adding to the case’s interest is the possibility that the robber is not old at all. The theory gained traction after a white Ohio man admitted to robbing several banks while wearing a mask that made him appear to be black.

It was so realistic that police mistakenly arrested a man who had similar facial characteristics. Even the wrongly accused man’s mother thought a photo she had seen of the robbery suspect on the news was her son.

The real culprit, Conrad Zdzierak, who pleaded guilty in November, said he bought the mask from SPFXMasks in California’s San Fernando Valley.

Another type of mask the firm makes is called “The Elder.” Its deep wrinkles and blemished skin bear a striking resemblance to the grizzled visage of the “Geezer Bandit.”

“There are some similarities, but that doesn’t mean that someone is wearing that particular mask,” FBI spokesman Darrell Foxworth said.

The FBI has spoken with the mask company but is not saying whether agents have tried to track customers. The agency says publicly that it is still looking for an old man, not someone with a silicone mask.

In some cases, witnesses reported seeing plastic tubes running from the robber’s nose to a bag housing what may have been a breathing apparatus.

If it turns out that the robber’s geezer credentials are real, he is part of a rare but persistent demographic of older bank robbers. Bank heists usually are committed by men younger than 50, Mr. Foxworth said, but there are plenty of exceptions.

In October, authorities snagged a man suspected of being the “Golden Years Bandit.” William McCormick Jr., 59, was arrested on suspicion of robbing five banks in the Los Angeles region.

A year earlier, “Baby Boomer Bandit” suspect Salvador Sanchez, 64, was arrested on suspicion of carrying out several robberies in Pasadena, Calif.

The FBI in Houston said Theresa Mary Gaas, who was 56 at the time of her 2009 arrest, robbed two banks, earning her the nickname of “Grandma Bandit.”