DENVER, Colo. -- The FBI has dubbed him "Bank Robber BOB."

BOB has successfully managed to rob five area banks since Aug. 14. The FBI said he was unsuccessful on Friday, however, when he tried to steal money from the Provenant Federal Credit Union located at 4001 W. 16th Ave.

"The bank robbery (Friday) was a little different and out of pattern. He actually vaulted the teller counter and was confronted by two of the bank employees. They had a struggle and he actually got injured in the fight," said Kathy White, FBI.

Video: Bank Employees Foil Serial Robber

White said BOB fled the scene with a head injury and left a trail of blood on his way out the door.

Surveillance cameras caught BOB on tape wearing slacks, cowboy boots, a blue shirt and a tie.

Normally BOB is in disguise wearing a cowboy hat, a wig and sometimes glasses.

"The Rocky Mountain Safe Streets Task Force is gonna track him down and they will arrest him," said White.

The employees who confronted him and area banks were unavailable for comment.

Police said they hope someone will recognize BOB and report him to police. If you have spotted him, call 303-629-7171.

BOB was seen fleeing the scene in a 1970's older-model pickup truck.