Orange County detectives and the FBI on Tuesday asked for the public’s help identifying a bank robber who told his victims to “keep smiling” as he robbed a Costa Mesa Citibank last week.

The so-called “Keep Smiling Bandit” earned his nicknamed during the Oct. 12 robbery at 234 E. 17th St. in Costa Mesa, and he was believed to have robbed a Tustin Citibank at 18232 Irvine Blvd. on Saturday.

A joint FBI-Orange County Sheriff’s Department Bank Robbery Apprehension Team asked for help identifying the man, described as white, in his early 30s, 5 foot 7 inches to 5 foot 9 inches tall, and weighing 140 to 150 pounds.

During both robberies, the “Keep Smiling Bandit” passed notes to a teller and verbally demanded cash, a news release distributed by the FBI stated. He wore eyeglasses and a baseball cap and was described as “nervous.”

No weapon was seen in the two robberies, but the robber’s note read, “Keep your hands away from the alarm or I’ll shoot.”

Anyone with information on the “Keep Smiling Bandit” was asked to call 911 or, in the Los Angeles area, call the FBI at 310 477-6565.