Duquesne Spy Ring The Duquesne Spy Ring is the largest espionage case in United States history that ended in convictions . A total of thirty - three members of a German espionage network headed by Frederick " Fritz " Joubert Duquesne were convicted after a lengthy espionage investigation by the Federal Bureau of Investigation ( FBI ) . Of those arrested on the charge of espionage , 19 pleaded guilty . The remaining 14 men who entered pleas of not guilty were brought to jury trial in Federal District Court , Brooklyn , New York , on September 3 , 1941 ; and all found guilty on December 13 , 1941 . On January 2 , 1942 , the group was sentenced to serve a total of over 300 years in prison . The German spies who formed the Duquesne spy ring were placed in key jobs in the United States to get information that could be used in the event of war and to carry out acts of sabotage : one person opened a restaurant and used his position to get information from his customers ; another person worked on an airline so that he could report Allied ships that were crossing the Atlantic Ocean ; others in the ring worked as delivery people so that they could deliver secret messages alongside normal messages . William G . Sebold , who had been recruited as a spy for Germany , was a major factor in the FBI ' s successful resolution of this case through his work as a double agent for the United States government . For nearly two years the FBI ran a radio station in New York for the ring , learning what Germany was sending to its spies in the United States while controlling the information that was being transmitted to Germany . Sebold ' s success as a counterespionage agent was demonstrated by the successful prosecution of the German agents . One German spymaster later commented that the ring ' s roundup delivered " the death blow " to their espionage efforts in the United States . FBI director J . Edgar Hoover called his concerted FBI swoop on Duquesne ' s ring the greatest spy roundup in U . S . history . The 1945 film " The House on 92nd Street " was a thinly disguised version of the " Duquesne Spy Ring " saga of 1941 , but differs from historical fact . It won screenwriter Charles G . Booth an Academy Award for the best original motion picture story . FBI agents . William Sebold ( double - agent ) . A native of Germany , William Sebold served in the Imperial 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 February 10 , 1936 , he became a naturalized citizen of the United States . Sebold returned to Germany in February 1939 to visit his mother in Mülheim . On arrival in Hamburg , he was approached by a member of the Gestapo who said that Sebold would be contacted in the near future . Sebold proceeded to Mülheim where he obtained employment . In September 1939 , a Dr . Gassner visited Sebold in Mülheim and interrogated him about military planes and equipment in the United States . He also asked Sebold to return to the United States as an agent for Germany . Subsequent visits by Dr . Gassner and a Dr . Renken , later identified as Major Nickolaus Ritter of the German Secret Service , persuaded Sebold to cooperate with the Reich because he feared reprisals against family members still living there . Ritter was the Abwehr officer in charge of espionage against the United States and Britain . Since Sebold ' s passport had been stolen shortly after his first visit from Gassner , Sebold went to the US consulate in Cologne , to obtain a new one . While there , Sebold secretly told consulate personnel about his future role as a German agent and expressed his wish to cooperate with the FBI when he got back to America . Sebold reported to Hamburg , where he was instructed in such areas as preparing coded messages and microphotograph s . On completion of training , he was given five microphotographs containing instructions for preparing a code and detailing the type of information he was to transmit to Germany from the United States . Sebold was told to retain two of the microphotographs and to deliver the other three to German operatives in the United States : Fritz Joubert Duquesne , Hermann Lang , and one other . After receiving final instructions , including using the assumed name Harry Sawyer , he sailed from Genoa , Italy , and arrived in New York City on February 8 , 1940 . The FBI had been advised of Sebold ' s expected arrival , his mission , and his intent to assist in identifying German agents in the United States . Under the guidance of special agents , Sebold established residence in New York City as Harry Sawyer . Also , an office was set up for him as a consulting diesel engineer , to be used as a cover in establishing contact with members of the spy ring . In selecting the office for Sebold , FBI agents ensured that they could observe any meetings taking place there . In May 1940 , a shortwave radio - transmitting station operated by FBI agents on Long Island established contact with the German shortwave station abroad . For 16 months it served as a main channel of communications between German spies in New York City and their superiors in Germany . During this time , the FBI ' s station transmitted over 300 messages to and received 200 messages from Germany . Sebold ' s life story as a double agent was first told in the 1943 book " Passport to Treason : The Inside Story of Spies in America " by Alan Hynd . William Gustav Friedemann . William Gustav Friedemann was a principal witness in the Duquesne case . He began working for the FBI as a fingerprint analyst in 1935 and later became an agent after identifying a crucial fingerprint in a kidnapping case . After World War II , he was assigned to Puerto Rico , where he pinpointed the group behind the assassination attempt on President Harry Truman . He died of cancer on August 23 , 1989 , in Stillwater , Oklahoma . Convicted members of Duquesne Spy Ring . Frederick " Fritz " Joubert Duquesne . Born in Cape Colony , South Africa , on September 21 , 1877 , and naturalized a citizen of the United States in 1913 , Fritz Joubert Duquesne was a Captain in the Second Boer War . He is also known as " " The man who killed Kitchener " " since he claimed to have sabotaged and sunk HMS " Hampshire " , on which Lord Kitchener was en route to Russia in 1916 . Duquesne was a German spy at the time and for this act he was awarded the Iron Cross . Duquesne was also implicated in fraudulent insurance claims , including one that resulted from a fire aboard the British steamship " Tennyson " which caused the vessel to sink on February 18 , 1916 . When he was arrested on November 17 , 1917 , he had in his possession a large file of news clippings concerning bomb explosions on ships , as well as a letter from the Assistant German Vice Consul at Managua , Nicaragua . The letter indicated that : " Captain Duquesne " was " one who has rendered considerable service to the German cause . " Duquesne was also ordered to assassinate the American , Frederick Russell Burnham , Chief of Scouts for the British Army ; however he failed to do so . In February 1940 , Duquesne was operating a business known as the " Air Terminals Company " in New York City . After establishing his first contact with Duquesne by letter , Sebold met with him in Duquesne ' s office . During their initial meeting , Duquesne , who was extremely concerned about the possibility of electronic surveillance devices being present in his office , gave Sebold a note stating 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 . Duquesne provided Sebold with information for transmittal to Germany during subsequent meetings , and the meetings which occurred in Sebold ' s office were filmed by FBI Agents . Duquesne , who was vehemently anti - British , submitted information dealing with national defense in America , the sailing of ships to British ports , and technology . He also regularly received money from Germany in payment for his services . On one occasion , Duquesne provided Sebold with photographs and specifications of a new type of bomb being produced in the United States . He claimed that he secured that material by secretly entering the DuPont plant in Wilmington , Delaware . Duquesne also explained how fires could be started in industrial plants . Much of the information Duquesne obtained was the result of his correspondence with industrial concerns . Representing himself as a student , he requested data concerning their products and manufacturing conditions . In a letter to the " Chemical Warfare Service " in Washington , D . C . , Duquesne requested information on a new gas mask . He identified himself as a " well - known , responsible and reputable writer and lecturer " . At the bottom of the letter , he wrote , " Don ' t be concerned if this information is confidential , because it will be in the hands of a good , patriotic citizen . " A short time later , the information he requested arrived in the mail and a week later it was being read by intelligence officers in Berlin . Duquesne was brought to trial and was convicted . He was sentenced to serve 18 years in prison on espionage charges , as well as a 2 - year concurrent sentence and payment of a $ 2 , 000 fine for violation of the Foreign Agents Registration Act . He served his sentence in Leavenworth Federal Penitentiary in Kansas where he was mistreated and beaten by inmates . In 1954 he was released due to ill health , having served 14 years , and died indigent , at City Hospital on Welfare Island ( now Roosevelt Island ) , New York City on 24 May 1956 at the age of 78 . Paul Bante . A native of Germany , Paul Bante served in the German army during World War I . He came to the United States in 1930 and became a naturalized U . S . citizen in 1938 . Bante , formerly a member of the German - American Bund , claimed that Germany put him in contact with one of their operatives , Paul Fehse , because of Bante ' s previous association with a Dr . Ignatz T . Griebl . Before fleeing to Germany to escape prosecution , Dr . Griebl had been implicated in a Nazi spy ring with Guenther Gustave Rumrich , who was tried on espionage charges in 1938 . Bante assisted Paul Fehse in obtaining information about ships bound for Britain with war materials and supplies . Bante claimed that as a member of the Gestapo his function was to create discontent among union workers , stating that every strike would assist Germany . Sebold met Bante at the Little Casino Restaurant , which was frequented by several members of this spy ring . During one such meeting , Bante advised that he was preparing a bomb fuse , and he subsequently delivered dynamite and detonation caps to Sebold . Entering a guilty plea to violation of the Foreign Agents Registration Act , Bante was sentenced to 18 months ' imprisonment and was fined $ 1 , 000 . Max Blank . Max Blank went to the United States from Germany in 1928 . Although he never became a U . S . citizen , Blank had been employed in New York City at a German library and at a book store which catered to German trade . Paul Fehse , a major figure in this case , informed Germany that Blank , who was acquainted with several members of the spy ring , could secure some valuable information but lacked the funds to do so . Later Fehse and Blank met with Sebold in his office . They told Sebold that Blank could obtain details about rubberized self - sealing airplane gasoline tanks , as well as a new braking device for airplanes , from a friend who worked in a shipyard . However , he needed money to get the information . Blank boasted to agent Sebold that he had been in the espionage business since 1936 , but that he had lost interest in recent years because payments from Germany had fallen off . Blank pleaded guilty to violation of the Foreign Agents Registration Act . He received a sentence of 18 months ' imprisonment and a $ 1 , 000 fine . Alfred E . Brokhoff . A native of Germany , Alfred E . Brokhoff , went to the United States in 1923 and became a naturalized citizen in 1929 . He was a mechanic for the United States Lines in New York City for 17 years prior to his arrest . Because of his employment on the docks , he knew almost all of the other agents in this group who were working as seamen on various ships . Brokhoff helped Fehse secure information about the sailing dates and cargoes of vessels destined for England . He also assisted Fehse in transmitting this information to Germany . Also , another German agent , George V . Leo Waalen , reported that he had received information from Brokhoff for transmittal to Germany . Upon conviction , Brokhoff was sentenced to serve a five - year prison term for violation of the espionage statutes and to serve a two - year concurrent sentence for violation of the Registration Act . Heinrich Clausing . In September 1934 , German - born Heinrich Clausing went to the United States , where he became a naturalized citizen in 1938 . Having served on various ships sailing from New York Harbor since his arrival in the country , he was employed as a cook on the SS " Argentine " at the time of his arrest . Closely associated with Franz Stigler , one of the principal contact men for this spy ring , Clausing operated as a courier . He transported microphotographs and other material from the United States to South American ports , from which the information was sent to Germany via Italian airlines . He also established a mail drop in South America for expeditious transmittal of information to Germany by mail . He signed his letters as " Carlos " . He received no money but spied to help Germany . Clausing was convicted and was sentenced to serve eight years for violation of espionage statutes . He also received a two - year concurrent sentence for violation of the Registration Act . Conradin Otto Dold . Conradin Otto Dold went to the United States from Germany in 1926 . He became a U . S . citizen in 1934 under the Seamen ' s Act . Prior to his arrest , he was Chief Steward aboard the SS " Siboney " of the American Export Lines . Dold was related to people holding high positions in Germany and was closely associated with other members of the espionage group who worked on ships sailing from New York Harbor . As a courier , Dold carried information from Nazi agents in the United States to contacts in neutral ports abroad for transmittal to Germany . Dold was sentenced to serve 10 years in prison on espionage charges and received a 2 - year concurrent sentence and a fine of $ 1 , 000 for violation of the Registration Act . Rudolf Ebeling . After leaving Germany for the United States in 1925 , Rudolf Ebeling was employed as a foreman in the Shipping Department of Harper and Brothers in New York City when he was arrested . Ebeling obtained information regarding ship sailings and cargoes , which he provided to Paul Fehse for transmittal to Germany . He also furnished such information to Leo Waalen , who delivered the material to Sebold for transmittal . Upon conviction , Ebeling was sentenced to 5 years in prison on espionage charges . He also received a 2 - year concurrent sentence and a $ 1 , 000 fine for violating the Registration Act . Richard Eichenlaub . Richard Eichenlaub , who went to the United States in 1930 and became a citizen in 1936 , operated the Little Casino Restaurant in the Yorkville Section of New York City . This restaurant was a rendezvous for many members of this spy ring , and Eichenlaub introduced several new members into the group . Eichenlaub reported to the Gestapo and often obtained information from his customers who were engaged in national defense production . Through Eichenlaub , dynamite was delivered to Sebold from Bante . Having entered a plea of guilty to violation of the Registration Act , Eichenlaub was sentenced to pay a fine of $ 1 , 000 and to serve 18 months in prison . Heinrich Carl Eilers . A native of Germany , Heinrich Carl Eilers went to the United States in 1923 and became a citizen in 1932 . From 1933 until his arrest , he served as a steward on ships sailing from New York City . Eilers made a trip from New York to Washington , D . C . , to obtain information for Germany from the Civil Aeronautics Authority . His mission , however , was unsuccessful . At the time of his arrest in New York City by Customs authorities in June 1940 , he had in his possession 20 letters addressed to people throughout Europe . He also had books relating to magnesium and aluminum alloys which had been sent to him by Edmund Carl Heine , one of the principal espionage agents in this group . Upon conviction , Eilers received a 5 - year prison sentence on espionage charges and a concurrent sentence of 2 years ' imprisonment and a $ 1 , 000 fine under the Registration Act . Paul Fehse . In 1934 , Paul Fehse left Germany for the United States , where he became a citizen in 1938 . Since his arrival in the United States , he had been employed as a cook aboard ships sailing from New York Harbor . Fehse was one of the directing forces in this espionage group . He arranged meetings , directed members ' activities , correlated information that had been developed , and arranged for its transmittal to Germany , chiefly through Sebold . Fehse , who was trained for espionage work in Hamburg , Germany , claimed he headed the Marine Division of the German espionage system in the United States . Having become quite apprehensive and nervous , Fehse made plans to leave the country . He obtained a position on the SS Siboney , which was scheduled to sail from Hoboken , New Jersey , for Lisbon , Portugal , on March 29 , 1941 . He planned to desert ship in Lisbon and return to Germany . However , before he could leave the United States , Fehse was arrested by FBI Agents . Upon arrest , he admitted sending letters to Italy for transmittal to Germany , as well as reporting the movements of British ships . On April 1 , 1941 , Fehse was sentenced on a plea of guilty to serve one year and one day in prison for violation of the Registration Act . He subsequently pleaded guilty to espionage and received a prison sentence of 15 years . Edmund Carl Heine . A native of Germany , Edmund Carl Heine went to the United States in 1914 and became a naturalized citizen in 1920 . Until 1938 , he held various positions in the foreign sales and service department of Ford Motor Company and Chrysler Corporation . His employment took him to the West Indies , South America , Spain , and Berlin , Germany . Heine was closely associated with Dr . Hans Luther , former German Ambassador in Washington , D . C . , and Prince Louis Ferdinand of Berlin . Heine sent letters from Detroit , Michigan , to Lilly Stein , one of the German spies Sebold was instructed to contact . The letters contained detailed technical data regarding the military , aircraft construction , and various industries . He also wrote to aircraft companies to obtain information about their production , number of employees , and the time required to construct military planes . Later it was discovered that Heine was also the mysterious " Heinrich " who supplied the spy ring with aerial photographs . After obtaining technical books relating to magnesium and aluminum alloys , Heine sent the materials to Heinrich Eilers . To ensure safe delivery of the books to Germany in case they did not reach Eilers , Heine indicated the return address on the package as the address of Lilly Stein . Upon conviction of violating the Registration Act , Heine received a $ 5 , 000 fine and a 2 - year prison sentence . Felix Jahnke . In 1924 , Felix Jahnke left Germany for the United States , where he became a naturalized citizen in 1930 . Jahnke had attended military school in Germany and had served in the German army as a radio operator . Jahnke and Axel Wheeler - Hill secured the services of Josef Klein , a radio technician , in building a portable radio set for Jahnke ' s apartment in the Bronx . Jahnke used this radio to transmit messages , which were intercepted by the FBI , to Germany . He also visited the docks in New York Harbor to obtain information about any vessels bound for England . After pleading guilty to violation of the Registration Act , Jahnke was sentenced to serve 20 months in prison and to pay a $ 1 , 000 fine . Gustav Wilhelm Kaercher . Gustav Wilhelm Kaercher went to the United States in 1923 , becoming a citizen in 1931 . He served in the German Army during World War I and was a former leader of the German Bund in New York . During visits to Germany , he was seen to have worn a German Army officer ' s uniform . At the time of his arrest , he was engaged in designing power plants for the American Gas and Electric Company in New York City . Kaercher was arrested with Paul Scholtz , who had just handed Kaercher a table of call letters and frequencies for transmitting information to Germany by radio . As a result of his guilty plea to charges of violating the Registration Act , Kaercher received a $ 2 , 000 fine and a prison sentence of 22 months . Josef Klein . A native of Germany , Josef Klein went to the United States in 1925 ; he did not become a citizen . Klein , a photographer and lithographer , had been interested in the building and operation of shortwave radio transmitters . Klein constructed a portable shortwave radio transmitting - and - receiving set for Felix Jahnke and Axel Wheeler - Hill . When he built the radio set , Klein knew it would be used for transmitting messages to Germany . Upon conviction , Klein received a sentence of five years ' imprisonment on espionage charges and a concurrent sentence of two years ' imprisonment under the Registration Act . Hartwig Richard Kleiss . Born in Germany , Hartwig Richard Kleiss went to the United States in 1925 and became a naturalized citizen six years later . Following his arrival in the United States , he was employed as a cook on various ships . Kleiss obtained information for Germany , including blueprints of the SS " America " which showed the locations of newly installed gun emplacements . He included information about how guns would be brought into position for firing . Kleiss also obtained details on the construction and performance of new speedboat s being developed by the United States Navy , which he submitted to Sebold for transmittal to Germany . Kleiss had originally chosen to stand trial . However , after cross - examination , he changed his plea to guilty on charge of espionage and received an eight - year prison sentence . Herman W . Lang . Herman W . Lang went to the United States from Germany in 1927 and became a citizen in 1939 . He was one of the four people Sebold had been told to contact in the United States . Until his arrest , Lang had been employed by the Carl L . Norden Corp . which manufactured the Top Secret Norden bombsight and other highly confidential materials essential to the national defense of the United States . The Norden had been considered a critical wartime instrument by the United States Army Air Forces and American bombardiers were required to take an oath during their training stating that they would defend its secret with their own life , if needed . During a visit to Germany in 1938 , Lang conferred with German military authorities and reconstructed plans of the confidential materials from memory . It is perhaps because of Lang that the bombsight instruments used by Luftwaffe bombers during the war were fairly similar to the United States ' Norden bombsight . The Lotfernrohr 3 and the BZG 2 in 1942 used a similar set of gyroscopes that provided a stabilized platform for the bombardier to sight through , although the more complex interaction between the bombsight and autopilot was not used . Later in the war , Luftwaffe bombers used the Carl Zeiss Lotfernrohr 7 , or Lotfe 7 , which had an advanced mechanical system similar to the Norden bombsight , but was much simpler to operate and maintain . Upon conviction , Lang received a sentence of 18 years in prison on espionage charges and a two - year concurrent sentence under the Registration Act . Evelyn Clayton Lewis . A native of Arkansas , Evelyn Clayton Lewis had been living with Fritz Joubert Duquesne in New York City . Lewis had expressed her anti - British and anti - Semitic feelings during her relationship with Duquesne . She was aware of his espionage activities and condoned them . While she was not active in obtaining information for Germany , she helped Duquesne prepare material for transmittal abroad . Upon a guilty plea , Lewis was sentenced to serve one year and one day in prison for violation of the Registration Act . Rene Emanuel Mezenen . Rene Emanuel Mezenen , a Frenchman , claimed U . S . citizenship through the naturalization of his father . Prior to his arrest , he was employed as a steward in the Pan American transatlantic clipper service . The German Intelligence Service in Lisbon , Portugal , asked Mezenen to act as a courier , transmitting information between the United States and Portugal on his regular commercial aircraft trips . As a steward he was able to deliver documents from New York to Lisbon in 24hrs . He accepted this offer for financial gain . In the course of flights across the Atlantic , Mezenen also reported his observance of convoys sailing for England . He also became involved in smuggling platinum from the United States to Portugal . When discussing his courier role with agent Sebold , Mezenen boasted that he hid the spy letters so well that if they were found it would have taken two to three weeks to repair the airplane . Following a plea of guilty , Mezenen received an eight - year prison term for espionage and two concurrent years for registration violations . Carl Reuper . Having come to the United States from Germany in 1929 , Carl Reuper became a citizen in 1936 . Prior to his arrest , he served as an inspector for the Westinghouse Electric Company in Newark , New Jersey . Reuper obtained photographs for Germany relating to national defense materials and construction , which he obtained from his employment . He arranged radio contact with Germany through the station established by Felix Jahnke . On one occasion , he conferred with Sebold regarding Sebold ' s facilities for communicating with German authorities . Upon conviction , Reuper was sentenced to 16 years ' imprisonment on espionage charges and 2 years ' concurrent sentence under the Registration Act . Everett Minster Roeder . Born in the Bronx , New York , Everette Minster Roeder was a draftsman and designer of confidential materials for the U . S . Army and Navy . Sebold had delivered microphotograph instructions to Roeder , as ordered by German authorities . Roeder and Sebold met in public places and proceeded to spots where they could talk privately . In 1936 , Roeder had visited Germany and was requested by German authorities to act as an espionage agent . Primarily due to monetary rewards he would receive , Roeder agreed . At the time of his arrest , Roeder had 16 guns in his home in Long Island , New York . Roeder entered a guilty plea to the charge of espionage and was sentenced to 16 years in prison . Paul Alfred W . Scholz . A German native , Paul Scholz went to the United States in 1926 but never attained citizenship . He had been employed in German book stores in New York City , where he disseminated Nazi propaganda . Scholz had arranged for Josef Klein to construct the radio set used by Felix Jahnke and Axel Wheeler - Hill . At the time of his arrest , Scholz had just given Gustav Wilhelm Kaercher a list of radio call letters and frequencies . He also encouraged members of this spy ring to secure data for Germany and arranged contacts between various German agents . Upon conviction , Scholz was sentenced to 16 years ' imprisonment for espionage with 2 years ' concurrent sentence under the Registration Act . George Gottlob Schuh . George Schuh , a native of Germany , went to the United States in 1923 . He became a citizen in 1939 and was employed as a carpenter . As a German agent , he sent information directly to the Gestapo in Hamburg from the United States . Schuh had provided Alfred Brokhoff information that Winston Churchill had arrived in the United States on the HMS King George V . He also furnished information to Germany concerning the movement of ships carrying materials and supplies to Britain . Having pleaded guilty to violation of the Registration Act , Schuh received a sentence of 18 months in prison and a $ 1 , 000 fine . Erwin Wilhelm Siegler . Erwin Wilhelm Siegler went to the United States from Germany in 1929 and attained citizenship in 1936 . He had served as chief butcher on the SS " America " until it was taken over by the U . S . Navy . A courier , Siegler brought microphotographic instructions to Sebold from German authorities on one occasion . He also had brought $ 2 , 900 from German contacts abroad to pay Lilly Stein , Duquesne , and Roeder for their services and to buy a bomb sight . He served the espionage group as an organizer and contact man , and he also obtained information about the movement of ships and military defense preparations at the Panama Canal . Subsequent to his conviction , Siegler was sentenced to 10 years ' imprisonment on espionage charges and a concurrent 2 - year term for violation of the Registration Act . Oscar Richard Stabler . Born in Germany , Oscar Richard Stabler went to the United States in 1923 and became a citizen in 1933 . He had been employed primarily as a barber aboard transoceanic ships . In December , 1940 , British authorities in Bermuda found a map of Gibraltar in his possession . He was detained for a short period before being released . A close associate of Conradin Otto Dold , Stabler served as a courier , transmitting information between German agents in the United States and contacts abroad . Stabler was convicted and sentenced to serve five years in prison for espionage and a two - year concurrent term under the Registration Act . Heinrich Stade . Heinrich Stade went to the United States from Germany in 1922 and became a citizen in 1929 . He had been a musician and publicity agent in New York . He told agent Sebold he had been in the German Gestapo since 1936 and boasted that he knew everything in the spy business . Stade had arranged for Paul Bante ' s contact with Sebold and had transmitted data to Germany regarding points of rendezvous for convoys carrying supplies to England . Stade was arrested while playing in the orchestra at an inn in Long Island , New York . Following a guilty plea to violation of the Registration Act , Stade was fined $ 1 , 000 and received a 15 - month prison sentence . Lilly Barbara Carola Stein . Born in Vienna , Austria , Lilly Stein met Hugo Sebold , the espionage instructor who had trained William Sebold ( the two men were not related ) in Hamburg , Germany . She enrolled in this school and was sent to the United States in 1939 . In New York , she worked as an artist ' s model and was said to have moved in New York ' s social circles . Stein was one of the people to whom Sebold had been instructed to deliver microphotograph instructions upon his arrival in the United States . She frequently met with Sebold to give him information for transmittal to Germany , and her address was used as a return address by other agents in mailing data for Germany . Stein pleaded guilty and received sentences of 10 years ' and 2 concurrent years ' imprisonment for violations of espionage and registration statutes , respectively . Franz Joseph Stigler . In 1931 , Franz Stigler left Germany for the United States , where he became a citizen in 1939 . He had been employed as a crew member and chief baker aboard U . S . ships until his discharge from the when the U . S . Navy converted that ship into . His constant companion was Erwin Siegler , and they operated as couriers in transmitting information between the United States and German agents aboard . Stigler sought to recruit amateur radio operators in the United States as channels of communication to German radio stations . He had also observed and reported defense preparations in the Panama Canal Zone and had met with other German Agents to advise them in their espionage pursuits . In January 1941 , Stigler asked agent Sebold to radio Germany that Prime Minister Winston Churchill had arrived secretly in the U . S . on the H . M . S . " King George V " with Lord Halifax . Upon conviction , Stigler was sentenced to serve 16 years in prison on espionage charges with 2 concurrent years for registration violations . Erich Strunck . A seaman aboard the ships of the United States Lines since his arrival in the United States , Erich Strunck went to the United States from Germany in 1927 . He became a naturalized citizen in 1935 . As a courier , Strunck carried messages between German agents in the United States and Europe . He requested authority to steal the diplomatic bag of a British officer traveling aboard his ship and to dispose of the officer by pushing him overboard . Sebold convinced him that it would be too risky to do so . Strunck was convicted and sentenced to serve 10 years in prison on espionage charges . He also was sentenced to serve a two - year concurrent term under the Registration Act . Leo Waalen . Leo Waalen was born in Danzig while that city was part of Germany . He entered the United States by " jumping ship " about 1935 . He was a painter for a small boat company which was constructing small craft for the U . S . Navy . Waalen gathered information about ships sailing for England . He also obtained a confidential booklet issued by the FBI which contained precautions to be taken by industrial plants to safeguard national defense materials from sabotage . Waalen also secured government contracts listing specifications for materials and equipment , as well as detailed sea charts of the United States Atlantic coastline . In May 1941 , the SS " Robin Moor " was carrying nine officers , 29 crewmen , seven or eight passengers , and a commercial cargo from New York to Mozambique via South Africa , without a protective convoy . On 21 May , the ship was stopped by " U - 69 " in the tropical Atlantic 750 miles west of the British - controlled port of Freetown , Sierra Leone . Although the SS " Robin Moor " was flying the flag of a neutral country , her mate was told by the U - boat crew that they had decided to " let us have it . " After a brief period for the ship ' s crew and passengers to board her four lifeboats , the U - boat fired a torpedo and then shelled the vacated ship . Once the ship sank beneath the waves , the submarine ' s crew pulled up to Captain W . E . Myers ' lifeboat , left him with four tins of ersatz bread and two tins of butter , and explained that the ship had been sunk because she was carrying supplies to Germany ' s enemy . In October 1941 , federal prosecutors adduced testimony that Leo Waalen , one of the fourteen accused men who had pled not guilty to all charges , had submitted the sailing date of the SS " Robin Moor " for radio transmission to Germany , five days before the ship began her final voyage . Following his conviction , Waalen was sentenced to 12 years in prison for espionage and a concurrent 2 - year term for violation of the Registration Act . Adolf Henry August Walischewski . A German native , Walischewski had been a seaman since maturity . He became a naturalized citizen in 1935 . Walischewski became connected with the German espionage system through Paul Fehse . His duties were confined to those of courier , carrying data from agents in the United States to contacts abroad . Upon conviction , Walischewski received a five - year prison sentence on espionage charges , as well as a two - year concurrent sentence under the Registration Act . Else Weustenfeld . Else Weustenfeld arrived in the United States from Germany in 1927 and became a citizen 10 years later . From 1935 until her arrest , she was a secretary for a law firm representing the German Consulate in New York City . Weustenfeld was thoroughly acquainted with the German espionage system and delivered funds to Duquesne which she had received from Lilly Stein , her close friend . She lived in New York City with Hans W . Ritter , a principal in the German espionage system . His brother , Nickolaus Ritter , was the " Dr . Renken " who had enlisted Sebold as a German agent . In 1940 , Weustenfeld visited Hans Ritter in Mexico , where he was serving as a paymaster for the German Intelligence Service . After pleading guilty , Else Weustenfeld was sentenced to five years ' imprisonment on charge of espionage and two concurrent years on a charge of registration violations . Axel Wheeler - Hill . Axel Wheeler - Hill went to the United States in 1923 from his native land of Russia . He was naturalized as a citizen in 1929 and was employed as a truck driver . Wheeler - Hill obtained information for Germany regarding ships sailing to Britain from New York Harbor . With Felix Jahnke , he enlisted the aid of Paul Scholz in building a radio set for sending coded messages to Germany . Following conviction , Wheeler - Hill was sentenced to serve 15 years in prison for espionage and 2 concurrent years under the Registration Act . Bertram Wolfgang Zenzinger . Born in Germany , Bertram Wolfgang Zenzinger went to the United States in 1940 as a naturalized citizen of the Union of South Africa . His reported reason for coming to the United States was to study mechanical dentistry in Los Angeles , California . In July , 1940 , Zenzinger received a pencil for preparing invisible messages for Germany in the mail from Siegler . He sent several letters to Germany through a mail drop in Sweden outlining details of national defense materials . Zenzinger was arrested by FBI Agents on April 16 , 1941 . Pleading guilty , he received 18 months in prison for violation of the Registration Act and 8 years ' imprisonment for espionage . References . Notes Sources