Daniel Frisiello was arrested on Thursday for sending a white powder-filled letter to Donald Trump Jr.’s Manhattan apartment last month that sent his wife, Vanessa, and two other people to the hospital for observation.

Frisiello’s Facebook page says he’s a program assistant at Catholic Charities Archdiocese of Boston and is filled with anti-President Donald Trump posts. His record also shows connections to the Democratic Party.

Police tracked him down after he sent another powder-laced letter to a university professor.

Fox News reported:

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.”

The letter was postmarked in Boston on Feb. 7, had an American flag stamp and no return address. The powder was ultimately determined to be corn starch, the Associated Press reported.

Frisiello allegedly sent five letters filled with white powder and is charged with “threat to injure the person of another and false information and hoaxes,” according to Fox News.

“In April 2016, he contributed $75 to ActBlue, a political action committee that works to raise money online for Democratic candidates and committees, according to the Federal Election Commission (FEC),” Fox News reported.

Frisiello also posted an article detailing one of his crimes on Facebook, which is now filled with comments denouncing him.

“Dude you actually posted about your own crime? Get help you,” one person wrote.

“Person going to prison for sending threats and powder…. liberal fart ass,” another person wrote.