DENVER -- The FBI is looking for a serial bank robber nicknamed Bank Robber Bob who investigators said has robbed at least six banks in the Denver Metro area.

The most recent robbery happened Tuesday at the Burlington Railroad Credit Union in Wheatridge.

FBI Spokeswoman Special Agent Kathy Wright said Bob would hand the teller a note demanding money and then run away.

The robber, described as a white man between 45 and 55 years old, has struck banks in Northglen, Centennial, Westminster, Wheat Ridge and Denver, the FBI said.

Wright said he is about 5 feet 8 inches tall with an average build. Bob may be wearing a dark wig, sunglasses and a baseball cap, she said.

The FBI asks that if anyone has information to contact the Rocky Mountain Safe Streets Task Force at 303-629-7171.