Investigators have not found ricin or ingredients for it in the house or vehicle of a Corinth man accused of mailing poisoned letters to President Obama, a senator and a local judge, an F.B.I. agent testified Monday.  http://www.nytimes.com/aponline/2013/04/23/us/ap-us-suspicious-letters.html?ref=us  A search of a computer belonging to the man, Paul K. Curtis, found no evidence that he […]