GOVERNMENT AGENTS meanwhile had again swept down on the Surratt boardinghouse and arrested everyone in the place. But the raid netted them only Mrs. Surratt, her daughter Anna, and some female boarders, all of whom, except Mrs. Surratt, were soon released. Just as the agents were about to take their prisoners away, a knock sounded at the door. Standing there was a rough-looking individual dressed like a day laborer, with a pickax on his shoulder. Arrested on suspicion, he proved to be Lewis Payne, the man who had attacked Seward.
Two more suspects were arrested elsewhere-- Samuel Arnold and Michael O'Laughlin. Then Atzerodt fell into the net. He had been detailed to murder Andrew Johnson but had lost his nerve. Edmund Spangler, a scene shifter at Ford's Theater, joined the swelling number of apprehended conspirators. Booth's pursuers arrested Dr. Samuel A. Mudd, who had set the actor's broken leg. It was now clear that Booth had headed south, and information from Detective Britton A. Hill confirmed Stanton's erroneous but persisting belief that the murder plot had originated in Richmond.
Stanton ordered Payne, O'Laughlin, Spangler, and Atzerodt confined below deck on the monitor Montauk, which was anchored close by the Navy Yard. The other male prisoners were placed in the hold of the monitor Saugus, riding near by. Each prisoner had an iron ball attached to his leg by a heavy chain and wore handcuffs joined by an iron bar. Later, for better security, Stanton ordered a canvas bag placed over each man's head and tied around his neck. A hole in the device allowed the prisoners to breathe and eat, but they were unable to see.