The FBI calls him the "Geezer Bandit" because he looks like an old man.  For two years federal agents have been on his trail.  They thought they were trying to nab somebody in his 60s or 70s but now it appears he may actually be much younger.

During a recent heist in San Luis Obispo, Calif., the Geezer Bandit got a surprise.  A teller was able to put a die pack in the bag of money that exploded as he was leaving the bank.

"When you look at the video and you see him sprint away from the bank parking lot, it would appear that the person who is running was running at a pretty good pace," says Darrell Foxworth at the FBI.

In fact the video seems to show somebody who was quite fit and young.

"You see him, in the video, drop to the ground, he scrambles around appearing to try to collect his belongings, collect some money, and other documents he had there in the bank and then he sprints out," explains Foxworth.

If it is a younger man, the disguise has worked.  He's pulled off 16  bank robberies in California.

And he's gained a following.  The Geezer Bandit Facebook page has close to 12,ooo fans.  They even sell Geezer merchandise now.

The FBI believes the robber bought his old man mask at SPFX, a Hollywood special effects company in Van Nuys, Calif.  SPFX made the mask Freddy Kruger wears in the Nightmare on Elm Street movies.  It wouldn't be the first time criminals have used masks made by SPFX.

"People have used our masks for illegal purposes," Judy Hammer at SPFX tells ABC News.

Recently a young Chinese defector used an elder mask made by the company to board a plane in Hong Kong and demand asylum in Canada.

Police served a search warrant on SPFX to get a list of who bought the old man mask. The FBI wants to know if the Geezer Bandit really is a geezer.