[1] Martin Monti Jr.'s father had immigrated to the United States from the Italian Graubünden, part of the Italian-speaking area of Switzerland, while his mother was a native of Italy.

[2] Martin James Monti's mother, Marie Antoinette Wiethaupt, was born in Missouri to German-American parents.

In the 1930s, Monti was a staunch anti-communist and an enthusiastic admirer of Charles Coughlin,[5] a Roman Catholic priest who made weekly radio broadcasts.

Coughlin was known for his sentiments towards anti-capitalism, anti-communism, antisemitism, and admiration of the fascist governments of Germany and Italy; his broadcasts attracted millions of listeners before eventually being stopped in 1939 on the outbreak of World War II.

While attached to the 126th Replacement Depot, Monti hitched a ride aboard a C-46 transport aircraft to Cairo, Egypt and, from there, traveled on to Italy, via Tripoli, Libya.

While there, he observed that an F-5E Lightning aircraft,[9] an unarmed photographic reconnaissance version of the P-38, was being serviced and would require a test flight after repairs.

Initially treated as an ordinary prisoner of war, he was able to convince his captors, including interrogator Hanns Scharff, that he had defected out of genuine conviction.

In late 1944, Monti made a microphone test at the recording studio of SS-Standarte Kurt Eggers, a propaganda unit of the Waffen-SS, under the direction of Gunter d'Alquen, in Berlin.

[11] In 1945, Monti participated in a radio program titled "The Round Table Conference", again at the SS-Standarte Kurt Eggers recording studio.

She then approached Adelburt Houben, her supervising radio official, to whom she gave an ultimatum: "That man (Monti) is a spy or a traitor, either he must go or I will."

While in the SS, Monti participated in the creation of a propaganda leaflet to be distributed by the Wehrmacht and among Allied prisoners of war.

[15] Upon arrival in Milan, Monti approached the first U.S. Army unit he encountered, while still wearing his SS uniform, from which by this point, he had removed all insignia and identifying marks.

"[16] During his post-war trials, Monti claimed he had stolen the plane to fight the Germans, was shot down, and joined with partisans, who gave him the SS uniform.

Only minutes later, the Federal Bureau of Investigation arrested him at Mitchel Field, New York, and charged him with treason for the propaganda activities performed as "Martin Wiethaupt".

Monti's lawyers had advised him to plead guilty, saying there was no hope of an acquittal and that his status as a military officer would constitute a major aggravating factor.

His attorney then asked for leniency, citing his upbringing in an extremist and isolationist environment that "fanatically imbued" him to identify Soviet Russia and Communism as the nation's principal enemy.

[23] In 1963, Monti attempted again to have his charges of treason reversed in a Brooklyn Federal Court, claiming he "only went to Germany to assassinate Adolf Hitler and end the war".