(CNN) A federal prosecutor used a routine press conference announcing criminal charges on Thursday to deliver a harsh message to those who advocate white supremacy and white nationalism.

Justin Herdman, the US attorney for the Northern District of Ohio, announced one count of transmitting threatening communications via interstate commerce against James Reardon, a self-described white nationalist

Reardon's Instagram account was filled with anti-Semitic slurs. One post included a video of a man shooting a rifle amid sirens and screams. It was tagged to the Jewish Community Center of Youngstown and captioned, "Police identified the Youngstown Jewish Family Community shooter as local white nationalist Seamus O'Rearedon," according to Andy Lipkin, executive vice president of the Youngstown Area Jewish Federation. Seamus O'Rearedon is a Gaelic version of Reardon's name.

Herdman, a former assistant district attorney in Manhattan, said he wanted to speak directly to those who support Reardon's views.

"Go ahead and make your case for Nazism, a white nation, and racial superiority," he said. "The Constitution may give you a voice, but it doesn't guarantee you a receptive audience. Your right to free speech does not automatically mean that people will agree with you. In fact, you have a God-given and inalienable right to be on the losing end of this argument.

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