The man alleged to have sent a letter to President Obama that tested positive for the poison ricin has been charged with threatening President Obama. The Justice Department announced the charges against Paul Kevin Curtis, 45, on Thursday.

Curtis, who has worked as an Elvis impersonator, was arrested on Wednesday as a suspect in the mailing of the suspicious letters to the president and U.S. Senator Roger Wicker, a Republican from Mississippi.

Wicker told reporters Thursday that he had once hired Curtis to perform as the hip-swiveling King of rock and roll at a party.

“I have indeed met him,” Wicker said. “He was very entertaining.”

“He was more stable then,” Wicker added.

An FBI bulletin obtained by NBC News on Wednesday indicated that both letters contained identical closing statements.

The letters, which were postmarked April 8, 2013, out of Memphis, Tenn., ended with the phrase, “to see a wrong and not expose it, is to become a silent partner to its continuance.” The letters were also signed the same: “I am KC and I approve this message.”

More from Pete Williams, Kasie Hunt and Matthew DeLuca, NBC News

Posted by Libergirl