Background on the Killian documents:
On Sept. 8, 2004, CBS’ 60 Minutes aired a feature “For the Record” exposing documents regarding President George W. Bush’s service in the Air National Guard. The documents were obtained from Lt. Col. Bill Burket and contained criticisms of Bush’s Guard service by his commander, late Lt. Col. Jerry B. Killian.
Dan Rather reported on the television program that the Killian documents were obtained from Killian’s personal files, and incorrectly asserted that the documents had been researched and thoroughly authenticated by CBS.
Immediately, the authenticity was challenged by typographers who said the documents could not have come from the time frame indicated because of the type face used in the documents. CBS had received a faxed copy of the documents from Burket, who when asked for the originals claimed he burned them after sending them to CBS.
CBS and Rather continued to defend the documents despite criticisms from analysts and competitor news organizations. Finally, after two weeks, CBS backed away from the claim that the documents were legitimate and fired several people including the producer responsible for that segment, Mary Mapes.
Dan Rather has been accused several times over the course of his career for having a "liberal media slant." The timing of the release of these documents came only two months before the 2004 Presidential election, which also presented itself as unfair accusations in light of an election.