At two o'clock in the morning of Saturday, the fifteenth, they burst into the house of Mrs. Surratt and displaying the bloody collar of the coat of the dying Lincoln, demanded the whereabouts of Booth and Surratt. It being presently discovered that Booth had escaped on horseback across the Navy Yard Bridge with David Herold ten minutes in his rear, a dash was made upon the livery-stables of Washington, their proprietors taken into custody, and then the whole of lower Maryland was invaded, the soldiers declaring martial law as they progressed. Ford's theatre was taken and held by an armed force, and the proprietor and employees were all swept into prison, including Edward Spangler, a scene-shifter, who had been a menial attendant of Booth's. The superstitious notion prevailed that the inanimate edifice whose walls had suffered such a desecration was in some vague sense an accomplice; the Secretary swore that no dramatic performance should ever take place there again; and the suspicion was sedulously kept alive that the manager and the whole force of the company must have aided their favorite actor, or the crime could not have been so easily perpetrated and the assassin escaped. On the night of the fifteenth (Saturday) a locked room in the Kirkwood House, where Vice President Johnson was stopping, which had been engaged by George A. Atzerodt on the morning of the fourteenth, was broken open, and in the bed were found a bowie-knife and a revolver, and on the wall a coat (subsequently identified as Herold's), in which was found, among other articles, a bank book of Booth's. The room had not been otherwise occupied--Atzerodt, after taking possession of it, having mysteriously disappeared. On the morning of the seventeenth (Monday), at Baltimore, Michael O'Laughlin was arrested as a friend of Booth's, and it was soon thought that he "_resembled extremely_" a certain suspicious stranger who, it was remembered, had been seen prowling about Secretary Stanton's residence on the night of the 13th, when the serenade took place, and there doing such an unusual act as inquiring for, and looking at, General Grant. On the same day at Fort Monroe, Samuel Arnold was arrested, whose letter signed "Sam" had been found on Saturday night among the effects of Booth.