Charge over Obama ricin letter

A martial arts instructor from Mississippi has been charged with attempting to use a biological weapon after ricin-laced letters were sent to Barack Obama and other officials.

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Letter addressed to Obama tests positive for ricin

Suspicious letter addressed to US President Obama has tested positive for the deadly poison ricin, as did a letter to a Republican Senator.

The FBI assessment is that there are no links between the poison letters to Obama and Senator Roger Wicker and the bombs at The Boston Marathon.

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