— A 27-year-old Cary man is facing federal charges after the U.S. Attorney's Office said he threatened to injure people in Cary over the weekend.

Garrett Asger Grimsley, of 3116 Lakeside View Court, allegedly posted an online public message on the messaging app Whisper, stating "don't go to Cary tomorrow," on Feb. 19, authorities said in paperwork released Tuesday.

In a follow-up private message conversation, Grimsley said the following:

“For too long the kuffar [non-Muslims] have spit in our faces and trampled our rights. This cannot continue. I cannot speak of anything. Say your dua [prayers], sleep, and watch the news tomorrow. It will only be the beginning . . .”

Authorities were able to track down Grimsley based on the geo-location of his post and a name and address provided by the cell phone carrier whose service was used to make the post.

When authorities entered Grimsley's home, they saw a Facebook conversation in which he was talking to another person about encrypting the hard drive on his computer and stating that he was expecting to be raided by police, warrants said.

A search warrant executed at Grimsley's apartment resulted in the recovery of an AK-47 rifle, four 30-round magazines and about 340 rounds of ammunition, authorities said.

"I am just shocked someone would want to kill us, that they had AK-47s and bombs and they were going to kill everyone that wasn't Muslim. It's shocking," said neighbor Kelly Biagianti.

Amanda Smith used to live in Grimsley's apartment before moving a few doors down and was questioned by agents.

"There were four men at the door and they said FBI, so we weren't sure what was going on," she said.

Smith said she only spoke once with Grimsley in passing and that he "seemed like a normal guy."

Grimsley appeared before a U.S. magistrate judge Tuesday and was charged with transmitting a threat in interstate commerce to injure a person. He is also charged with cyberstalking by the Cary Police Department.

Authorities said Grimsley was removed from the Wake County Detention Center and taken into federal custody Tuesday night.

If convicted, Grimsley could face a maximum penalty of five years jail time and a $250,000 fine.

The case is being investigated by the FBI, the Cary Police Department and the North Carolina State Bureau of Investigation.