Authorities say a California bank robber branded "The Geezer Bandit" because he appeared to be old might actually be wearing a mask, and the mask may have been damaged after a recent robbery.
FBI spokeswoman Laura Eimiller said Friday the man also was seen running away from his latest heist this month.
The disclosures raise questions about the age of the man suspected of holding up 16 California banks from San Luis Obispo to San Diego.
Investigators have been stymied for more than two years by the bandit, previously believed to be in his 60s or 70s.
The most recent robbery was Dec. 2 in San Luis Obispo when a security dye-pack exploded as the man left the bank and sprinted away.
The FBI this week released new surveillance video of the dye-pack explosion, NBC Los Angeles reported.
The video shows a man walking next to a truck after robbing a Bank of America in San Luis Obispo and becoming surrounded with what looks like red smoke, according to the FBI.
The smoke is actually red dye that came from a dye pack, which is a security device that's implanted in a stack of money to help authorities catch bank robbers by staining them and stunning them.
"You see him drop to the ground, trying to gather some of his belongings and also the money that he stole," said FBI Special Agent Darrell Foxworth.
What happened next may be further proof that The Geezer Bandit is much younger than he appears, Foxworth said. In the video, you can see the man sprinting across the parking lot.
"When you look at that, it would lead you to believe that he doesn't appear to be someone in his 60s or 70s running at that fast of a pace," said Foxworth.
For the past two years since the Geezer robberies began, the FBI has been in contact with companies that make life-like elderly masks, hoping a sales receipt could lead to the Geezer Bandit, Foxworth said.
The mask may have been damaged by the explosion, according to the FBI.
"If it's not made of the right material then (the dye) could permanently stain it, in such a way that it's very noticeable," said Foxworth.
In images taken from inside the bank, the Geezer Bandit is seen carrying his signature day planner against his body, where he hides his gun.
The Geezer left behind the day planner after the dye-pack explosion, according to the FBI. It is now undergoing a forensic examination.
The Geezer Bandit has robbed 16 banks, including 11 in San Diego County. There is a $20,000 reward leading to his capture and conviction.
This article includes reporting from NBCLosAngeles.com and The Associated Press.