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WASHINGTON -- Letters sent to President Barack Obama and a Mississippi senator that tested positive for poisonous ricin are related and both are postmarked Memphis, Tenn., the FBI said Wednesday. A senator said police have a suspect in mind. Several…

First responders tend to the wounded, including a young boy in a wheelchair, where two explosions occurred along the final stretch of the Boston Marathon on Monday. Dr. David Mooney sees bleeding children all the time. As director of the…

An envelope addressed to Sen. Roger Wicker of Mississippi twice tested positive Tuesday for ricin, a potentially fatal poison, congressional officials said, heightening concerns about terrorism a day after a bombing at the Boston Marathon.