John Matthews, an actor who grew up with John Wilkes Booth, ran into his childhood chum on Pennsylvania Avenue on April 14, 1865. Booth asked him to mail a letter to a newspaper editor for him if he didn’t see him the next day.
Matthews forgot all about the letter in his overcoat pocket until it fell out onto the floor — after the assassination. Matthews ripped open the letter, realized it was Booth’s confession and manifesto, and prompty burned it until it was unreadable.
He told his priest about the letter. Fr. Francis Boyle, a politically savvy assistant pastor, suggested Matthews skip to Canada immediately and stay there.
Sources: Newspaper accounts and “A Parish for the Federal City” by Morris J. MacGregor