The Killian documents controversy (also referred to as Memogate or Rathergate) involved six purported documents critical of U.S. President George W. Bush's service in the Air National Guard in 1972–73. Four of these documents were presented as authentic in a 60 Minutes II broadcast aired by CBS on September 8, 2004, less than two months before the 2004 Presidential Election, but it was later found that CBS had failed to authenticate the documents. Subsequently, several typewriter and typography experts concluded the documents were forgeries. No forensic document examiners or typography experts have authenticated the documents, and this may not be technically possible without the original documents. The purveyor of the documents, Lt. Col. Bill Burkett, claims to have burned the originals after faxing copies to CBS.
CBS News producer Mary Mapes obtained the copied documents from Burkett, a former officer in the Texas Army National Guard, while pursuing a story about the George W. Bush military service controversy. The papers, purportedly made by Bush's commander, the late Lieutenant Colonel Jerry B. Killian, included criticisms of Bush's service in the Guard during the 1970s. In the 60 Minutes segment, anchor Dan Rather stated: "We are told [the documents] were taken from Lieutenant Colonel Killian’s personal files" and incorrectly asserted that "the material" had been authenticated by experts retained by CBS.
The authenticity of the documents was challenged within hours on Internet forums and blogs, with questions initially focused on alleged anachronisms in the documents' typography. Content soon spread to the mass media. Although CBS and Rather defended the authenticity and usage of the documents for a two-week period, continued scrutiny from other news organizations and independent analysis of the documents obtained by USA Today and CBS raised questions about their validity and led to a public repudiation on September 20, 2004. Rather stated, "if I knew then what I know now – I would not have gone ahead with the story as it was aired, and I certainly would not have used the documents in question," and CBS News President Andrew Heyward said, "Based on what we now know, CBS News cannot prove that the documents are authentic, which is the only acceptable journalistic standard to justify using them in the report. We should not have used them. That was a mistake, which we deeply regret."