10. The FBI allowed Dasch to return to his Mayflower Hotel room following hours of questioning.
Ladd and agent Duane Taylor interrogated Dasch for hours. One of the first pieces of information Dasch provided was where Burger was staying in New York. Before Dasch’s initial interview was over FBI agents in New York were following Burger. Burger left the hotel to meet with Heinck and Quirin in a clothing store, and the FBI took the opportunity to arrest all three. With Dasch in Washington, the other three members of the northern team were in custody. The explosives which they had brought ashore had been found by the Coast Guard, and turned over to the FBI. They had been in the United States less than one week.
In a June 22 memo to the President, J. Edgar Hoover announced the arrests of the four Germans, the exposure of the plot, and the role of the FBI in protecting the United States from immeasurable harm. He omitted to mention that the plot had been related to the FBI through an unsolicited confession by one of its members. In the memo, the FBI received all credit for uncovering the plot through their own investigative means. Hoover mentioned that there were others connected to the sabotage scheme yet to be taken into custody, and asked for continued secrecy. The problem was that the FBI had no idea where the other saboteurs were, and neither did any of the men they had in custody.