A letter addressed to President Barack Obama containing a suspicious substance was intercepted and is being tested, according to the Secret Service.
Tuesday, the FBI said that a envelope testing positive for ricin, a deadly poison, was intercepted at the U.S. Capitol and addressed to Sen. Roger Wicker (R-MS).
In the first case, the letter was intercepted at a postal facility in Maryland that screens mail sent to Congress, and never reached Wicker’s office.
Sen. Wicker thanked law enforcement and said an investigation was underway. The White House's mail is screened at a separate, offsite facility.