The recent Secret Service fiasco in Colombia made me think about John Frederick Parker, one of the original Washington D.C. police officers, who was fired in 1868 for literally sleeping on the job. (He had earlier been acquitted of charges of dereliction of duty and visiting prostitutes.) It was in 1865, however, when Parker had the costliest lapse of his stumblefuck career. From an article about his death in the July 20, 1890 Brooklyn Daily Eagle:

“The one man in the world who could have prevented the assassination of President Lincoln is dead. John Fredrick Parker, born in Winchester, Va., came to Washington some time before the firing upon Fort Sumter and soon found employment upon the metropolitan police force. When in 1862 it was decided to strengthen the regular force of doorkeepers and watchmen at the White House with a squad of policemen, Parker was one of those selected. It thus happened that when President Lincoln and party entered the old Ford Theater on the night of Good Friday, 1865, they were accompanied by Parker as guard. He took the position at the door to the private box from which President Lincoln watched the performance, where he was expected to remain and prevent the entrance of every one except the members of the party. As the play proceeded Parker from his post could hear just enough of what was said on the stage to arouse his curiosity, and it was not long before he left the door and edged his way toward the auditorium. He finally took a seat in the orchestra, or ‘pit’ as it was then called, where he had scarcely settled himself when the whole audience was surprised by the report of a pistol shot. The assassin, Booth, had stealthily approached the door of the president’s private box, where, finding no one to challenge him, he entered unannounced and fired the fatal shot. There is no question in the minds of those who are familiar with the details that had Parker remained at his post Booth could never had taken President Lincoln unawares.”