The so-called "Tiger Bandit" is suspected of robbing a U.S. Bank branch Friday in Lomita, the sixth robbery since last Friday he has been linked to.
The robber was described as a black or Latino man with a stocky build and dark complexion and possibly a skin condition, said Laura Eimiller of the FBI.
During the robberies, the suspect demands cash in various denominations, Eimiller said.
"Investigators believe there is a possibility that the Tiger Bandit may actually be two men working together, but entering banks separately," Eimiller said.
Robberies linked to the Tiger Bandit occurred in Cerritos last Friday, Long Beach and Marina del Rey Saturday, Santa Monica on Tuesday and Thursday in Huntington Beach. Friday's robbery occurred at 2270 Pacific Coast Highway, Eimiller said.
The Tiger Bandit received his nickname because he can be seen wearing a Detroit Tigers baseball hat in bank surveillance photos, Eimiller said.
Authorities urged anyone with information regarding the suspect's whereabouts to call 911 or (888) 226-8443.