On Wednesday, the FBI, along with police chiefs from the cities that were hit by the bandit, came together to announce a $100,000 reward for information leading to an arrest.
Detectives say the suspect may have had prior weapons training, which leads them to believe he may have ties to law enforcement or the military. He's been dubbed the "AK-47 Bandit" because of the assault rifle he uses during the holdups.
It's been almost a year since the Chino bank robbery. On Feb. 29, 2012, the suspect held up the California Bank & Trust on 5455 Riverside Drive. A police officer was shot while in the process of checking on the bank after a caller - possibly the gunman - phoned in a fake bomb threat.
"Anytime an AK-47 wound is experienced, it's usually very, very traumatic, and that's been the case with our officer," said Chino Police Chief Miles Pruitt. "It's been extremely traumatic for him and his family."
Pruitt said the officer is back on "light duty."
Authorities say the bandit is suspected in a total of five bank heists, the most recent one in Rexburg, Idaho.
"At one point during our robbery, the suspect made mention that he had shot a police officer before, and he also stated that he had been an officer," said Rexburg Police Chief Shane Turman.
Investigators are concerned because in each of the robberies, the gunman has entered the banks pointing his weapon at employees and customers. During a robbery at a Chase Bank in North Bend, Wash., police say the suspect aimed his assault rifle at a small child because the child made a noise.
"This guy is a time bomb about to go off again," said FBI Asst. Director Bill Lewis.
The suspect is described as about 5-foot-10, 180 to 200 pounds, between the ages of 25 and 40. He wears a mask, but witnesses described him as having blue eyes brighter than the average person.
His getaway vehicle in the California robbery was described as a 2009-2011 Nissan Maxima with a chrome package. In another robbery, he was seen driving away in a Jeep Libery with a reddish-orange paint job.
Anyone with information is urged to call the FBI at (855) 9-BANDIT.