William G. Sebold



William G. Sebold (Wilhelm Georg Debrowski; 10 March 1899 in Mülheim, Germany – February 1970 in Walnut Creek, California) was a German spy in the United States during World War II, who became a double agent for the FBI.

Early life
Sebold served in the German army during World War I. After leaving Germany in 1921, he worked in industrial and aircraft plants throughout the United States and South America. On 10 February 1936, he became a naturalized citizen of the United States.

He returned to Germany in February 1939 to visit his mother in Mülheim. Upon his arrival in Hamburg, Germany, he was approached by a Gestapo agent who said that Sebold would be contacted in the near future. Sebold proceeded to Mülheim where he obtained employment.

Espionage


In September 1939, a Dr. Gassner visited Sebold in Mülheim and interrogated him regarding military planes and equipment in the United States. He also asked Sebold to return to the United States as an espionage agent for Germany. After additional visits by Dr. Gassner and a "Dr. Renken" (later identified as Major Nickolaus Ritter of the Abwehr), Sebold agreed to spy for Germany, being blackmailed with information that he had omitted spending some time in a German jail when applying for American citizenship. Ritter was the Abwehr officer in charge of espionage against the United States and Britain. Sebold received final instructions from Ritter, including the use of codes and microphotographs. Sebold was then assigned the alias "Harry Sawyer", the code name TRAMP, and Abwehr number A.3549.

Before leaving Germany, Sebold went to the U.S. Consulate in Cologne, Germany. He told the consular officials about his future role as a German spy. He also expressed his wish to cooperate with the Federal Bureau of Investigation (FBI) in the United States. The U.S. government agreed.

Sebold sailed from Genoa, Italy, and arrived in New York City on 8 February 1940. There, Sebold (with secret help from the FBI) set himself up as a consulting engineer, with an office on 42nd Street in Manhattan. The FBI, forewarned of Sebold's arrival, set up Sebold's office so that they could record all conversations there, and even observe and film any meetings taking place (via a one-way mirror).

Duquesne Spy Ring
Sebold was instructed by the Abwehr to contact Fritz Joubert Duquesne, code-named DUNN, a German spy in New York. Duquesne had been a spy for Germany since World War I; before that, he had been a Boer spy in the Second Boer War.

At their first meeting, Duquesne, who was extremely worried about bugs and microphones in Sebold's office, gave Sebold a note suggesting that they should talk elsewhere. After relocating to an Automat, the two men exchanged information about members of the German espionage system with whom they had been in contact.

In May 1940, FBI agents on Long Island set up a shortwave radio station, and established contact with the Abwehr's radio station in Germany, posing as part of Sebold's spy ring. For 16 months this radio station was a main channel of communication between German spies in New York City and the Abwehr. During this time, the FBI's radio station transmitted over 300 messages to Germany, and received 200 messages from Germany. Through Sebold, the U.S. identified dozens of German agents in the United States, Mexico and South America.

In June 1941, all of Sebold's activities were stopped when the FBI arrested 33 German agents detected as a result of his activities. Of those arrested on the charge of espionage, 19 pleaded guilty. The 14 men who pled not guilty were tried in Federal District Court, Brooklyn, New York, on 3 September 1941; and they were all found guilty by the jury on 13 December 1941. The thirty-three members of the Duquesne Spy Ring were sentenced to serve a total of over 300 years in prison. Duquesne himself was sentenced to 18 years in prison. The Duquesne Spy Ring remains the largest espionage case in U.S. history that ended in convictions.

Sebold's success as a counterespionage agent is demonstrated by the successful prosecution of these 33 German agents. However, once the trial ended, Sebold disappeared. He is said to have entered a government witness protection program and assumed another identity.

One of the earliest books to detail Sebold's career as a double agent was Alan Hynd's 1943 Passport to Treason: The Inside Story of Spies in America.

Peter Duffy, author of The Bielski Brothers and The Killing of Major Denis Mahon: A Mystery of Old Ireland, is writing a book about Sebold for Scribner, a division of Simon and Schuster.