The Massachusetts man who allegedly mailed a white powder to Donald Trump Jr. has previously donated to a Democratic political action committee and shared anti-Trump posts on social media, including comparing President Donald Trump to Adolf Hitler.

Daniel Frisiello, 24, was arrested Thursday after authorities tracked him down following the examination of a “glitter bomb” letter sent to Stanford University law professor Michele Dauber. Investigators matched the text font from the letter to other threats sent to those seen on the letters of the white-powder envelopes.

Authorities said the letter included a threatening note that read: “You are an awful, awful person. I am surprised that your father lets you speak on TV. You the family idiot. Eric looks smart.”

Trump Jr.’s wife, Vanessa Trump, opened the letter in the couple’s New York City apartment Feb. 12 and reported feeling nauseous and coughing. President Trump’s daughter-in-law and two other people were taken to a hospital in the incident.

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