OXFORD, Miss. — Investigators haven't found any ricin in the house of a Mississippi man accused of mailing poisoned letters to President Barack Obama, a U.S. senator and a local judge, according to testimony Monday from an FBI agent.

Agent Brandon Grant said that a search of Paul Kevin Curtis' vehicle and house in Corinth, Miss., on Friday did not turn up ricin, ingredients for the poison, or devices used to make it. A search of Curtis' computers has found no evidence so far that he researched making ricin.

Defense lawyers for Curtis say investigators' failure to find any ricin means the government should release their client. That lack of physical evidence could loom large as a detention and preliminary hearing continues Tuesday morning.


Still, Grant testified that authorities believe that they have the right suspect.

He testified that there were indentations on the letters which, when analyzed under a light source, turned out to be for Curtis' former addresses in Booneville and Tupelo, though the street name in one of the addresses was spelled wrong.