Letter Sent to Senator Tests Positive for Ricin Envelope for Roger Wicker intercepted at mail-sorting facility By John Johnson, Newser Staff Posted Apr 16, 2013 5:54 PM CDT 41 comments Comments A file photo of Sen. Roger Wicker, R-Miss. (AP Photo/Manuel Balce Ceneta, File) (Newser) – Scary story breaking out of DC: A letter addressed to Republican Mississippi Sen. Roger Wicker tested positive for the poison ricin, reports Politico. The envelope never got to him, reports CNN, which says it was intercepted at an off-site facility that sorts mail for the Capitol. Three separate tests turned up positive for the highly toxic poison. Authorities have identified a suspect, said Sen. Claire McCaskill, adding only that it was someone who writes lots of letters to lawmakers. It's not clear why the apparent target was Wicker, described by the Washington Post as a "low-profile senator in his second term." (He replaced Trent Lott in 2008.) The envelope got detected at a facility set up in 2001 after some senators were sent letters tainted with anthrax. "The bottom line is, the process we have in place worked," said McCaskill. FBI chief Robert Mueller and Homeland Security chief Janet Napolitano briefed senators today, though it's not clear when the letter was received.