U.S. federal prosecutors have dropped charges against a Mississippi man suspected of sending poisoned letters to President Barack Obama and to a U.S. senator.
A lawyer for Paul Kevin Curtis say investigators have turned their attention to another suspect whose house they already have searched. The attorney said investigators could find no evidence that Curtis was involved.
Federal agents arrested Curtis last week after letters tainted with the deadly poison ricin turned up at facilities that handle mail for the White House and Congress. One letter was addressed to President Obama and another to Republican Senator Roger Wicker of Mississippi. A Mississippi state judge also was threatened.
Investigators said they found no trace of ricin or the tools they think could have created it in Curtis's home or car, and no Internet searches for how to make the drug on his computer.
Curtis was released on Tuesday. He told reporters that the past week has been a nightmare. He said he loves his country and respects President Obama.