Fox News reporter Chad Pergram has tweeted that the letter sent to Barack Obama and the letter sent to Senator Roger Wicker yesterday - which tested positive for the poison ricin - contained 'similar language' and were 'signed identically'.
Letters sent to Obama & Wicker contain similar language and are signed identically.
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Gary Davies, 50, is believed to have known the victim, 56.
The couple, married for more than half a century, had recently retired to Mount Pleasant.
Four EU countries in eastern Europe refused to take part in the meeting