An envelope addressed to President Obama containing ricin, a deadly poison, was intercepted at a Maryland post office. Multiple suspicious packages were also sent to senators. The FBI determined ricin was in the letter to Obama, though it was not in a form that could easily enter the body. "I am KC and I approve this message" was signed on the letters. Ricin is highly toxic and lethal even in small amounts if inhaled or ingested. An Elvis impersonator named Kevin Curtis was initially arrested but released, and the FBI then arrested martial arts instructor James Everett Dutschke, whose studio tested positive for ricin.