Three of four field tests conducted on the powder inside the envelope addressed to Wicker tested positive for a protein that later tests determined to be ricin , a lethal toxin , it says . NEW : Man charged `` vehemently denies the allegations against him , '' his lawyer says . No illness reported from the letters yet , the FBI says . Comment: Envelopes were addressed to President Obama , a judge , Sen. Roger Wicker .
NEW : Man charged `` vehemently denies the allegations against him , '' his lawyer says . No illness reported from the letters yet , the FBI says . Comment: Envelopes were addressed to President Obama , a judge , Sen. Roger Wicker .