By Daniel Strauss and Vicki Needham - 04/17/13 11:52 PM EDT
FBI agents have arrested a suspect in connection with the ricin-filled letters sent to Sen. Roger Wicker (R-Miss.) and President Obama, officials confirmed to The Hill.
Mississippian Paul Kevin Curtis was arrested at 6:15 p.m. ET for sending two letters to Washington and one to a state official, according to the FBI. His home, in Corinth, Miss., is approximately two hours away from Memphis, where the letters were mailed.
The Secret Service said the letter sent to Obama was discovered at a remote White House mail screening facility.
"This facility routinely identifies letters or parcels that require secondary screening or scientific testing before delivery," the Secret Service said in a statement. "The Secret Service White House mail screening facility is a remote facility, not located near the White House complex, that all White House mail goes through."
“Gayle and I want to thank the men and women of the FBI and U.S. Capitol Police for their professionalism and decisive action in keeping our family and staff safe from harm," Wicker said in a statement after the arrest.
"My offices in Mississippi and Washington remain open for business to all Mississippians. We particularly want to thank the people of Mississippi for their thoughts and prayers during this time.”
The Associated Press cites an FBI bulletin that states both letters, postmarked April 8, 2013, were out of Memphis, Tenn., and included the same phrase: "to see a wrong and not expose it, is to become a silent partner to its continuance."
Both letters were also signed: "I am KC and I approve this message," the news service reported.
During a news conference Wednesday night, Lee County, Miss., Sheriff Jim H. Johnson said the suspect, whom he would not identify, “was cooperative at this point.”
The investigation was conducted by FBI Joint Terrorism Task Forces in Memphis, Tenn., and Jackson, Miss.; the U.S. Capitol Police; the U.S. Postal Inspection Service; and the U.S. Secret Service, according to an FBI release. It was aided by several state and local agencies.
A full analysis of the substance found in the letters is currently underway and is expected to take 24 to 48 hours, the FBI added.
Senate Sergeant at Arms Terry Gainer said the investigative follow-up is "significant and ongoing."
"There has been an arrest as a result of great work by the USCP [U.S. Capitol Police] in developing the information on the suspect, forensic work by several partners and dogged street work by the FBI," he said.
Curtis describes himself as a singer-songwriter on his Facebook page, and there are YouTube videos of him as an Elvis impersonator.
His apparent Twitter account followed a variety of public figures, including Sen. John McCain (R-Ariz.), former Rep. Gabrielle Giffords (D-Ariz.), former Vice President Al Gore, HBO's Bill Maher, and various media figures. In a posting online signed Kevin Curtis, he says he talked to Wicker about a legal case he had brought. Curtis said in the posting that Wicker "seemed very nervous while speaking with me and would make a fast exit to the door."
A photo of Curtis online shows him giving a thumbs-up by a bumper sticker that reads, "Christian and a Democrat."
LL Liberty 1885, a blog, noted that Curtis also claimed that he sent letters to Wicker, former Sen. Trent Lott (R-Miss.) and Sen. Thad Cochran (R-Miss.), but "never heard a word from anyone."
Lott on Thursday told The Hill he doesn't know Curtis, but said he had talked to Wicker about him. Wicker said Curtis comes from "a good family," but has "mental problems," according to Lott.
Meanwhile, Sen. Carl Levin (D-Mich.), whose Saginaw, Mich., office was evacuated Wednesday after receiving a suspicious letter, said in a statement Thursday that the FBI said preliminary tests on the letter were negative.
Bob Cusack contriibuted to this report, which was last updated at 11:43 a.m. Thursday.