( CNN ) -- Thrust into the headlines last week , accused of sending ricin-tainted letters to President Barack Obama and two other officials , Paul Kevin Curtis is a free man again . `` It 's like a train has been lifted off my shoulders , '' Curtis told CNN 's `` Piers Morgan Live '' on Tuesday . `` I 'm overwhelmed . I 'm extremely happy to be vindicated and out and able to see my kids . '' Charges were dropped and `` new information '' became available , U.S. Attorney Felicia Adams said . Authorities are investigating whether someone may have tried to falsely implicate the Elvis impersonator from Corinth , Mississippi , a law enforcement source said on condition of anonymity . Curtis was arrested April 17 and charged with sending a threat to the president last week after letters containing the poison triggered security scares around Washington . Former ricin suspect happy with vindication . Curtis said his arrest was surreal . `` It looked like a scene out of a movie , '' said Curtis , adding that there were hooded men with machine guns . `` I was just overwhelmed . I just kept asking , 'what is ricin ? What did I do ? ' '' Curtis ' attorney , Christi McCoy , said her client has been framed by someone who used several phrases Curtis likes to use on social media . The letters read , in part : `` To see a wrong and not expose it , is to become a silent partner to its continuance . '' They were signed `` I am KC and I approve this message , '' a source told CNN . They each had a Memphis , Tennessee , postmark and no return address . McCoy said she was sure someone else was to blame . `` I do believe that someone who was familiar and is familiar with Kevin just simply took his personal information and did this to him , '' McCoy said . `` It is absolutely horrific that someone would do this . '' Curtis said it was an eye-opener for him . `` I think now , how many people are thrown in jail because of circumstantial evidence and someone can frame you that easily , '' he said . Curtis had been accused of sending letters containing `` a suspicious granular substance '' to Obama ; Sen. Roger Wicker , R-Mississippi ; and Sadie Holland , a Justice Court judge in Lee County , Mississippi . The FBI said the substance tested positive for ricin , a toxin derived from castor beans that has no known antidote . No illnesses had been found as a result of exposure to the toxin . Watch Piers Morgan Live weeknights 9 p.m . ET . For the latest from Piers Morgan click here .
`` I 'm overwhelmed . I 'm extremely happy to be vindicated , '' he says . New information has come to light , U.S. attorney says . Source says investigators are looking at someone trying to frame him . Comment: