The third and most recent robbery was Saturday, September 19 at the Chase Bank in Hawthorne.
They are considered armed and dangerous.
Laura Eimiller at the F.B.I.'s Los Angeles Field Office says there's a reward for information leading to the trio's arrest.
Anyone with information is urged to contact the F.B.I. at 1-800-CANT HIDE or call local police.
City News Service contributed to this report.