Donald Trump’s Son Receives Threatening Letter in the Mail

Authorities in New York are investigating a threat Donald Trump’s son, Eric Trump, received in the mail.

Eric Trump’s wife opened the letter Thursday night at their Manhattan apartment and discovered a powdery substance inside, according to the Washington Post.

The letter had a Massachusetts postmark and a warning that if Donald Trump did not drop out of the presidential race soon, harm could come to the family’s children, according to an unnamed source cited by CBS News.

A preliminary test of the substance inside the envelope indicated that it was not hazardous, but it has been sent to a lab for testing, CBS reported.

Trump, the frontrunner for the Republican presidential nomination, has been running an anti-establishment campaign with outspoken views on everything from immigration to the economy.