The FBI’s Fake Office Put Nazi Spies on Film

Fritz Duquesne worried about hidden microphones. At his first meeting with William Sebold in New York, the veteran German spy passed a note suggesting they should talk elsewhere. They moved to an Automat. Later, Duquesne walked into Sebold’s office and described the defence information he could deliver. FBI cameras were watching through a two-way mirror.

Sebold’s return to America had begun with coercion. Visiting Germany in 1939, the naturalised American was pressed into intelligence work. The FBI’s history describes his fear of reprisals against relatives. Historian Sam Lebovic identifies another threat: exposure of a youthful conviction omitted from his immigration history. Sebold informed the American consulate before leaving.

The Germans trained him in coded messages and microphotography. He arrived in New York on 8 February 1940, using the name Harry Sawyer and a diesel-engineering consultancy as cover. The supposed German agent was now helping the FBI identify the people Germany expected him to meet.

His communications channel belonged to the Bureau. FBI engineers built a shortwave station on Long Island and established contact with Germany in May 1940. Over sixteen months, agents posing as Sebold sent more than 300 messages and received about 200. German headquarters was exchanging traffic with its target’s counterintelligence service.

The office completed the trap. Lebovic places Sebold’s dummy business in room 627 of the Knickerbocker Building near Times Square, with FBI agents in adjoining rooms. Hidden microphones and a filming position behind the mirror turned apparently private meetings into a record investigators could revisit.

Duquesne supplied photographs and specifications for an American bomb, claiming to have obtained them by entering a DuPont plant. He also discussed setting fires at industrial sites. Another visitor delivered dynamite and detonating caps. These were concrete exchanges for the Bureau to document alongside the reports passing over its radio.

By 13 December 1941, all 33 defendants in the ring had pleaded guilty or been convicted. The FBI records sentences totalling more than 300 years the following January. Later judgments changed part of that result: Lebovic records Edmund Heine’s successful appeal after his aviation reports proved to consist of publicly available information. The filmed meetings and the limits of the prosecutions belong to the same history.