John Semer Farnsworth was a former United States Navy officer who was convicted of spying for Japan during the 1930s. Arrested on July 14 1936, he was charged with selling confidential information to the Japanese. Farnsworth was sentenced to 4-12 years in prison.
From: (https://en.wikipedia.org/wiki/John_Semer_Farnsworth)
Betrayal from the East, the Inside Story of Japanese Spies in America by 