Federal officials said a letter addressed to a U.S. senator had been discovered to contain a potential poison. It was intercepted at an off-site facility in Landover where congressional mail has been examined before delivery since anthrax-laced letters were sent to Capitol Hill in 2001.The letter was addressed to Sen. Roger Wicker (R-Miss.) and tested positive for ricin, but officials familiar with the case gave no indication why the letter was sent to the second-term senator.
Ricin-laced letter sent to Miss. senator - The Washington Post