RIVERSIDE (CBSLA.com) — A bank robber dubbed the “Button-down Bandit” is wanted in connection with four Southern California heists over the past four weeks.

The bandit’s most recent bank robbery took place Monday at a U.S. Bank branch in Riverside, FBI officials said. The suspect is believed to have also committed robberies in Yorba Linda on Nov. 15, in Seal Beach on Nov. 25 and in La Quinta on Nov. 27.

According to the FBI, the Button-down Bandit enters banks, gives a demand note to a teller and makes statements including, “Don’t make me do it,” or “You have 30 seconds.” His notes have also demanded cash in denominations of $50s and $100s, suggesting that someone would otherwise get hurt.

The Button-down Bandit, apparently named for the button-down shirts he is seen wearing during each robbery, is described as a white man between 45 and 50 years old. He has white hair, a slender build and is between 150 and 160 pounds.

Anyone with information about the suspect’s identity can call their nearest FBI office, dial 911 or contact the agency through www.labankrobbers.org.