Manuel Jose Hernandez, 28, of Los Angeles had eluded authorities for weeks after allegedly robbing four banks in Los Angeles County, authorities said.
He reportedly entered a Chase bank in the 2000 block of South Victoria Avenue in Ventura, the same building that houses the county's FBI offices on the second floor.
She handed him roughly $1,700 in cash and activated the silent alarm, which immediately put FBI agents and local police on notice.
Agents spotted the suspect, who was holding the black nylon bag, running from the bank, so they gave chase, authorities said.
He told authorities he needed money and "that at least he didn't use any force during the robbery," according to the criminal complaint.
After reviewing surveillance photographs and information regarding other robberies, investigators said they believe Hernandez is responsible for four other bank robberies in Pasadena, Temple City, South El Monte and, mostly recently, Manhattan Beach.
In all four robberies, the bandit made off with roughly $16,300, according to the criminal complaint.