They've dubbed him the "Hoodie Bandit" and he's suspected of robbing three banks in Santa Rosa and Rohnert Park.
The FBI released his picture Wednesday, captured on a security camera, showing a man described as age 25 to 30 and wearing a gray hooded sweatshirt over a black baseball cap.
He's the suspect in the robbery of a Fulton Road Chase Bank in Santa Rosa on Feb. 1. Two weeks later, on Feb. 14, he hit a US Bank on Commerce Boulevard in Rohnert Park and a US Bank on Mendocino Avenue in Santa Rosa, the FBI said.
Along with the federal agents, Santa Rosa and Rohnert Park police are searching for him and seeking help identifying him.
He is known to use a note demanding money and "may be sporting a black goatee," the FBI said in a press release.
He is described as a white or Latino male who is between 5-foot-5 and 5-foot-7 and weighs 175 to 200 pounds.
After the Feb. 1 robbery, he was seen getting into a 1990s model Jeep Wrangler with faded red paint and a black hardtop.
Anyone with information can call the FBI 24 hours a day at (415) 553-7400.