By David Ingram and Deborah Charles
(Reuters) - Federal prosecutors filed criminal charges on Thursday against a Mississippi man, who worked as an Elvis impersonator, for threatening to harm President Barack Obama by sending him a letter that initially tested positive for the deadly poison ricin.
Paul Kevin Curtis, 45, was believed to have sent three letters, all with identical wording and type-written on yellow paper, to Obama, U.S. Senator Roger Wicker of Mississippi and Justice Court Judge Sadie Holland of Lee County, Mississippi.
The FBI confirmed the presence of ricin in the letters to Obama and Wicker, but said it is "not aware of any illness as a result of exposure to these letters."
A criminal complaint filed in U.S. District Court for the Northern District of Mississippi charged Curtis with threatening to harm Obama and making other threats through the U.S. Postal Service.
If convicted, Curtis, of Corinth, Mississippi, faces maximum penalties of 15 years in prison and $500,000 in fines plus three years supervised release.
Wearing handcuffs and leg shackles, Curtis appeared in court in Oxford, Mississippi. Local media reported that he made no comments except to say "yes ma'am" when the judge asked if he understood what was happening. His lawyer told reporters outside the court that Curtis was not guilty.
The Oxford Eagle newspaper said the government was requesting that Curtis be held without bond because they believe he is a "danger to the community."
Curtis struggled for years with mental illness and had stopped taking medication for a bipolar diagnosis, according to a statement from the Curtis family released on Thursday by Kevin Curtis' lawyer.
The poison scare put Washington on edge the same week that bombings at the Boston Marathon killed three people and injured 176 on Monday, but the FBI said there was no indication the incidents were connected.
Though no new incidents were reported on Thursday, officials were jittery on Capitol Hill this week as several lawmakers reported receiving suspicious letters or packages. Law enforcement officials shut down parts of two Senate buildings on Wednesday in response to the suspicious items which proved harmless.
Senate Sergeant at Arms Terrance Gainer issued a statement on Wednesday urging caution and understanding "during this time of heightened alert."
SAME THREATENING LETTER
According to an affidavit signed by FBI Special Agent Brandon Grant and Secret Service Special Agent Victor Dickerson, all three letters contained a "suspicious granular substance" and the same eight line threatening message:
"No one wanted to listen to me before.
There are still 'Missing Pieces'
Maybe I have your attention now
Even if that means someone must die
This must stop.
To see a wrong and not expose it,
Is to become a silent partner to its continuance
I am KC and I approve this message."
In September 2010, Curtis posted on his blog that he was writing a novel about black-market body parts titled "Missing Pieces."
The letter to Wicker, which arrived at the Senate Mail Facility in Landover, Maryland, without a return address, was discovered on Tuesday.
Wicker told reporters he had hired Curtis once as an Elvis impersonator. "I have indeed met the gentleman before," the Capitol Hill newspaper Roll Call cited Wicker as saying. "He's an Elvis impersonator. He entertained at a party my wife and I helped give for a young couple that were getting married. Quite entertaining."
The affidavit by the FBI and Secret Service agents said field tests of the suspicious substance in Wicker's letter had given mixed results, but further testing by the Laboratory Response Network - set up to help ensure an effective laboratory response to bioterrorism - showed the substance was "highly reactive" for ricin.
Ricin is a lethal poison found naturally in castor beans, but it takes a deliberate act to convert it into a biological weapon. Ricin can cause death within 36 to 72 hours from exposure to an amount as small as a pinhead.
No known antidote exists and the affidavit said it is extremely difficult to detect as the cause of death.
There was another ricin scare at the U.S. Capitol in 2004, when tests showed positive on a letter in a Senate mail room that served the office of Bill Frist, a Tennessee Republican who was then Senate majority leader.
The affidavit said Curtis had previously sent multiple communications to Wicker's office that included the phrase "this is Kevin Curtis and I approve this message".
The letter to Obama was also found on Tuesday and a field test showed the substance was positive for ricin. There was no return address on the envelope which, like the others, was postmarked on April 8 in Memphis, Tennessee.
The letter to Holland contained a granular substance like the others, although that substance has not yet been tested. Her letter was the only one that was delivered; the two addressed to Obama and Wicker were stopped at outside mail facilities.
Police in Booneville, Mississippi said Curtis had been investigated on several occasions. The affidavit cited one instance in 2007 when his ex-wife said Curtis was "extremely delusional, anti-government and felt the government was spying on him with drones."
(Writing by Deborah Charles; editing by Christopher Wilson)