The man, 58-year-old Robert Pratersch of Kissimmee, in September 2018 left three voicemail messages at Sanders' Vermont office where he made anti-Semitic threats and threatened to kill Sanders by beheading him in an "ISIS-style" video.
Pratersch was convicted in April of threatening a federal official and making threats over interstate communications media in April. He could have been sentenced to as much as 15 years in prison.
A public defender representing Pratersch did not immediately respond to a request for comment.