The U.S. Postal Service is now leading the investigation and told KPIX-TV that Richard Tillman is the brother of Pat Tillman. U.S. Postal Inspector Matthew Norfleet told the outlet that the motive for the alleged arson is under investigation. Photos from the scene show the words "Viva la me" were spray-painted on the front of the building.

A driver was arrested on Sunday for crashing a vehicle into a post office in San Jose, Calif., and setting the building ablaze, the authorities said.