Letter threatening to kill Trumps family if he doesn't drop out containing white powder sent to Trumps son

 A suspicious piece of mail containing white powder was sent to Eric Trump's New York City apartment Thursday, a Trump Organization source told ABC News.

A preliminary field test indicated the substance did not appear hazardous, according to the source, who was briefed on the matter.



The New York Police Department confirmed to ABC News it responded to a call at Trump Parc East, a high-end residential building on Central Park South, but the department did not identify the recipient of the letter as Donald Trump's 32-year-old son, who has an apartment in the building. (The Trump Organization source, however, confirmed the letter was indeed sent to the real estate mogul's son's apartment.)



The NYPD said, "At approximately 7:15 p.m., the NYPD responded to a residential building at 100 Central Park South to investigate a report of a suspicious letter received by a tenant. The letter has been removed and is being examined by law enforcement authorities. No injuries have been reported in connection with this incident."



The letter carried a Boston postmark. When Lara Trump, Eric's wife, opened the letter in their kitchen, white powder fell out, according to the source briefed on the matter.



The handwritten note said: "If you father does not drop out of the race, the next envelope won't be a fake." It was signed "X".



A source briefed on the investigation told ABC News that U.S. Secret Service protection only extends to Donald Trump at the moment.



"Protection is for him alone at this point," the source said.