Envelope sent to US senator said to test positive for ricin

WASHINGTON - An envelope sent to Republican Senator Roger Wicker of Mississippi tested positive for ricin, Senator Dick Durbin told reporters after a group of lawmakers were briefed by the FBI.
Ricin is a lethal poison found naturally in castor beans.
A spokeswoman for Wicker referred inquiries to US Capitol Police. A spokesman for Capitol Police could not immediately be reached for comment.