CORINTH, MISSISSIPPI (TIP): A man accused of mailing letters with suspected ricin to national leaders believed he had uncovered a conspiracy to sell human body parts on the black market and claimed “various parties within the government” were trying to ruin his reputation. Paul Kevin Curtis, 45, is charged with threatening President Barack Obama and others, according to a Thursday news release from the US department of justice. He is scheduled to appear in federal court on the two charges later on April 18, and if convicted could face up to 15 years in prison An affidavit says the letters sent to Obama, U.S. Sen.

Roger Wicker and a judge in Mississippi told the recipients: “Maybe I have your attention now even if that means someone must die.” Curtis was arrested April 17 at his home in Corinth, Mississipi. Curtis had been living in Corinth, a city of about 14,000 in extreme northeastern Mississippi, since December, but local police had not had any contact with him prior to his arrest, Corinth Police Department Capt. Ralph Dance told The Associated Press on Thursday. Dance said the department aided the FBI during the arrest and that Curtis did not resist being taken into custody. Since Curtis arrived in the town, he had been living in “government housing,” Dance said. He did not elaborate.

Police maintained a perimeter Thursday around Curtis’ home, and federal investigators were expected to search the house later in the morning, said local officers on the scene who declined to be identified. Four men who appeared to be investigators were in the neighborhood to speak to neighbors. There didn’t appear to be any hazardous-material crews, and no neighbors were evacuated. The material discovered in a letter to Wicker has been confirmed through field testing and laboratory testing to contain ricin, said Senate Sergeant-at-Arms Terrance Gainer.

The FBI has not yet reported the results of its own testing of materials sent to Wicker and to President Barack Obama. “Our field tests indicate it was ricin. Our lab tests confirm it was ricin. So I don’t get why others are continuing to use equivocal words about this,” Gainer said. Preliminary field tests can often show false positives for ricin. Ricin is derived from the castor plant that makes castor oil. There is no antidote, and it’s deadliest when inhaled.

The material sent to Wicker was not weaponized, Gainer said. An FBI intelligence bulletin obtained by The Associated Press said the two letters were postmarked Memphis, Tennessee. Both letters said: “To see a wrong and not expose it, is to become a silent partner to its continuance.” Both were signed, “I am KC and I approve this message.” The letters had Washington on edge in the days after the Boston Marathon bombing. As authorities scurried to investigate three questionable packages discovered in Senate office buildings on April 17, reports of suspicious items also came in from at least three senators’ offices in their home states. The items were found to be harmless. In addition, a Mississippi state lawmaker, Democratic Rep.

Steve Holland, said Wednesday night that his 80- year-old mother, Judge Sadie Holland, received a threatening letter last week with a substance that has been sent to a lab for testing. He said this letter was also signed “K.C.” “She opened it herself” on April 11 and told Holland about it three days later, Holland said. He said she had not been to the doctor, but he planned to take her on April 18. “She’s fine,” Holland said. “She’s had no symptoms.” Curtis’ neighbors, who said he did not seem violent, were concerned about their safety on April 18 and worried by the idea that someone was making poison in a house that sits so close to their bedrooms and front yards.