Ricin suspect believed he was in 'secret war' WASHINGTON - In the early-morning hours before he was arrested on suspicion of sending a poison-laced letter to the president of the United States, Paul Kevin Curtis was typing messages on his Facebook profile. Over the previous few days, the 45-year-old part-time singer had posted photos of fellow Buddy Holly and Roy Orbison impersonators, snapshots of buxom women and a certificate welcoming him to Mensa, a society for people with high IQs. At 5 a.m. Wednesday, about 12 hours before his arrest, he wrote, "I'm on the hidden front lines of a secret war. A war that is making Billions of dollars for corrupt mafia related organizations and people. (bone, tissue, organ, body parts harvesting black market) when we lay our loved ones to rest. Dozens of online postings that investigators believe were written by Curtis show he was convinced government agencies were out to ruin his reputation and torpedo his hopes of having a country music career. In 1999, Curtis opened a freezer door at the hospital in Tupelo, Miss., where he worked, and saw body parts. He became convinced he had uncovered a plot to sell organs on the black market, according to his postings online. For the next decade, Curtis tried to persuade government officials to investigate, writing letters and approaching officials at public events. He self-published a novel about the conspiracy called, "Missing Pieces." Curtis' father, Jack Curtis, reached by phone Thursday at his home in Cleveland, Miss., said his son was mentally troubled but not violent. His son, who goes by Kevin, began taking medication for bipolar disorder after he was fired from his job at the hospital, Curtis said. The FBI arrested Curtis shortly after 5 p.m. Wednesday, just before he was planning to pick up his four children from his ex-wife's house for a church service, his father said. At least two letters that Curtis is accused of mailing tested positive for ricin, a poison than can be made from castor plants. He was charged Thursday with knowingly using the U.S. mail to threaten the president and others. He could face up to 15 years in prison and a maximum fine of $500,000. He is charged with sending similar letters to Sen. Roger Wicker (R-Miss.) and a county judge. Prosecutors could add additional charges later. Jack Curtis said his son never talked with him about politics, Wicker or President Obama. He suspects someone may be trying to frame his son, who moonlights as an impersonator of Elvis and other famous singers. "The impersonator, as far as I'm concerned, could have been impersonated," he said. "My son is not a violent person whatsoever," Curtis said. Never has been. He's the baby of the family and extremely [musically] talented. According to the charging documents, the typewritten letter sent to Obama read, "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." The letter was postmarked Memphis, Tenn., on April 8, and ends with the phrase: "I am KC and I approve this message." Curtis used similar phrases in the other two letters and on his website and Facebook page, according to the affidavit. One of the many public officials Curtis had appealed to for help was Wicker, who helped pay for Curtis to perform as Elvis at a friend's wedding about 10 years ago. "He entertained at a party that my wife and I held for a young couple that was getting married," Wicker told reporters Thursday. He was quite entertaining. My impression is that since that time he's had mental issues. He's not as stable as he was back then. Curtis described the events at the hospital on a consumer-reporting website called "Ripoff Report" in 2007. In the report, he says he sent letters to Mississippi Republican officials including Sen. Thad Cochran, former Sen. Trent Lott and Wicker, who was then a congressman. "I never heard a word from anyone," he wrote. He says he spoke with Wicker several times at events where he performed, but that Wicker "seemed very nervous while speaking with me and would make a fast exit to the door when I engaged in conversation leading up to my case against [the hospital]." Mark Pitcavage, director of investigative research for the Anti-Defamation League, which tracks anti-government extremists, said Curtis did not seem that different from many individuals in the U.S. who appear to be motivated by "some real or perceived grievance against the government and become very obsessed." "They can act out their obsessions for years but not typically act violent on them," Pitcavage said. If Curtis is the person who sent the ricin letters, he could be someone who decided to act out in a violent fashion based on those obsessions. Curtis was known to police in Mississippi, according to court documents. In 2007, the Booneville Police Department investigated Curtis after his wife reported he was "extremely delusional, anti-government, and felt the government was spying on him with drones," according to an FBI and Secret Service affidavit filed with the U.S. District Court for the Northern District of Mississippi. Michael A. Memoli in the Washington bureau contributed to this report.