OXFORD, Miss. — The investigation into poisoned letters mailed to President Obama and others has shifted from an Elvis impersonator to his longtime foe, and authorities must now figure out if an online feud between the two men might have escalated into something more sinister.
Paul Kevin Curtis, 45, was released from a Mississippi jail on Tuesday and charges against him were dropped, nearly a week after authorities charged him with sending ricin-laced letters to the president, Republican US Senator Roger Wicker of Mississippi, and an 80-year-old Lee County, Miss., Justice Court judge, Sadie Holland.
Before Curtis left jail, the authorities had already descended on the home of 41-year-old Everett Dutschke in Tupelo, a Northeast Mississippi town best known as the birthplace of the King himself. On Wednesday, they searched the site of a Tupelo martial arts studio once operated by Dutschke, who has not been arrested or charged.
His attorney, Lori Nail Basham, said Dutschke is ‘‘cooperating fully’’ with investigators and that no arrest warrant had been issued.
Curtis, who performs as Elvis and other celebrities, describes a bizarre, yearslong feud between the two, but Dutschke insists he had nothing to do with the letters. They contained language identical to that found on Curtis’s Facebook page and other websites, making him an early suspect.
Federal authorities have not said what led them to drop the charges against Curtis, and his lawyers say they are not sure what new evidence the FBI has found.
After being released from jail Tuesday, Curtis described a long feud between himself and Dutschke, but said he is not sure exactly what started it. It involves the men’s time working together, a broken promise to help with a book by Curtis, and an acrimonious exchange of e-mails, Curtis said.
The two worked together at Curtis’s brother’s insurance office years ago, Curtis said. He said Dutschke told him he owned a newspaper and showed interest in publishing his book, called ‘‘Missing Pieces,’’ about what Curtis considers an underground market to sell body parts.
But Dutschke decided not to publish the material, Curtis said, and later began stalking him on the Internet.
Dutschke said he did not know Curtis that well.
‘‘He almost had my sympathy until I found out that he was trying to blame somebody else,’’ Dutschke said Monday.
‘‘I’ve known he was disturbed for a long time. Last time we had any contact with each other was at some point in 2010 when I threatened to sue him for fraud for posting a Mensa certificate that is a lie. He is not a Mensa member. That certificate is a lie.’’
Curtis acknowledges posting a fake Mensa certificate on Facebook but says it was an online trap set up for Dutschke because he believed Dutschke was stalking him online. He knew Dutschke also claimed to be a member of the organization for people with high IQs.
Dutschke had a Mensa e-mail address during his 2007 legislative campaign.
Dutschke started a campaign to prove him a liar, Curtis said, and allegedly harassed him through e-mails and social networking.
Curtis said the two agreed to meet at one point to face off in person, but Dutschke did not show up.
‘‘The last e-mail I got from him, was, ‘Come back tomorrow at 7 and the results of you being splattered all over the pavement will be public for the world to see what a blank, blank, blank you are.’ And then at that point, I knew I was dealing with a coward,’’ Curtis said.
Hal Neilson, one of the attorneys for Curtis, has said the defense gave authorities a list of people who may have had a reason to hurt Curtis, and that Dutschke’s name came up.
Efforts to reach Curtis, his lawyers, and his brother were unsuccessful on Wednesday.
Both men say they have met Wicker, and they each have a connection to Holland.
Authorities say the letters were mailed on April 8, but the one sent to Holland was the only one to make it into the hands of an intended target.
Her son, Democratic state Representative Steve Holland of Plantersville, said his mother did a ‘‘smell test’’ of the envelope and a substance in it irritated her nose.
The judge was not sickened by what authorities say was a crude form of the poison, which is derived from castor beans.