(CNN) -- A former officer in the Texas National Guard said Thursday he once overheard a conversation in which there was a request to sanitize President Bush's Guard records during Bush's tenure as Texas governor. Soon afterward, he said, he saw Bush's Guard performance review in a trash can. Bush served in the Texas Air National Guard during the Vietnam War era. Retired Lt. Col. Bill Burkett, who was then an adviser to the Texas adjutant general, who in that capacity serves as the commander of the state's National Guard, made the allegations. He said that in 1997 he overheard...