The FBI was created 43 years after Abraham Lincoln's death, and yet his assassin has ... an FBI file? Yep, a file was opened into John Wilkes Booth in 1922 and was still active as late as 1977, Smithsonian reports. The blog Wonders & Marvels got hold of the file, and shares some highlights. The file was started when a Missourian wrote bureau Director William J. Burns saying that Booth—rumored by some to still be alive—was either the man's neighbor or corresponding with his neighbor. Burns replied that he believed the "official records" and saw no need for further action.
Yet another letter the following year prompted Burns to read a book about Booth's alleged escape, and Burns found that it had "very strong evidence in support of the old belief that Booth did escape and live many years." (Still, there's no evidence of Burns following up on it.) In 1948, the FBI received the boot Booth wore when he killed Lincoln (a doctor removed it from his injured left leg), but an ultraviolet and infrared examination of writing in the boot couldn't make heads or tails of it. Finally, in 1977, the FBI scanned Booth's diary in search of invisible writing, and couldn't find any. The FBI did confirm what had been known since 1867, though: twenty-seven sheets were missing from it. The diary can still be seen at Ford's Theatre Museum. (In other Lincoln news, a report found in a box at the National Archives in 2012 revealed how the first doctor to reach the shot president reacted.)