Only one Florida resident was arrested and convicted by the United States government for performing German inspired espionage in Florida during World War II. This one misguided individual was forty-nine year old Carl Herman Schroetter, with aliases John Charles Post and Captain Jack Post. He was arrested at his residence, 220 Northwest 33rd. Avenue, Miami, Florida, on September 2, 1941, by special agents of the Federal Bureau of Investigation. Upon arraignment before the United States Commissioner at Miami, Schroetter was charged with gathering and mailing information concerning the national defense to another German agent, Kurt Frederick Ludwig, in New York City. Ludwig then transmitted the information by secret ink and code communication to German agents in Spain and Portugal, and from there it was relayed to Germany.
Prior, Leon O.
"German Espionage in Florida During World War II,"
Florida Historical Quarterly: Vol. 39:
4, Article 6.
Available at: https://stars.library.ucf.edu/fhq/vol39/iss4/6