The FBI believes it has the right man this time in the tangled case of the ricin-laced letters mailed to President Obama and two other public officials. In the early-morning darkness Saturday, four days after authorities dropped charges against an Elvis impersonator in Mississippi, FBI agents arrested a man the impersonator had been feuding with — a former radio announcer and onetime candidate for the state legislature who recently was charged with child molestation.

James Everett Dutschke, 41, was taken into custody about 12:50 a.m. Saturday at his home in Tupelo, Miss., the FBI said. He could face life in prison on federal charges of “knowingly developing, producing, stockpiling, transferring, acquiring, retaining and possessing a biological agent, toxin and delivery system, for use as a weapon,” according to the U.S. Attorney’s Office in Oxford, Miss.

Dutschke proclaimed his innocence last week, saying he had cooperated with investigators and insisting he had no idea how to manufacture ricin, a toxin derived from the castor bean plant that can kill quickly if inhaled. Lori Nail Basham, Dutschke’s attorney, declined to comment Saturday on her client’s arrest.

Dutschke had been the target of the investigation since the release from jail last week of Paul Kevin Curtis, 45, of Corinth, Miss. Curtis is the Elvis impersonator whom federal investigators initially charged with sending the poison letters to Obama, U.S. Sen. Roger Wicker (R-Miss.) and Lee County Justice Court Judge Sadie Holland.

Holland said in a phone interview Saturday that she can’t imagine why Dutschke would have wanted to send her a poisoned letter, as authorities allege — “I have no earthly idea” — but that she does remember having one unpleasant encounter with him.

In 2007, Dutschke ran as a Republican candidate for the Mississippi House of Representatives against her son, state Rep. Steve Holland, a Democrat. The judge said she attended a rally at which Dutschke excoriated her son’s performance in office. She confronted him afterward.

“I told him: ‘This is no way to run a campaign. You need to tell the people what you will do and what you have done. Don’t run your opponent down,’ ” she said.

Days later, she said, Dutschke came to her office and apologized to her. His candidacy was not successful.

Earlier this month, Holland went to work and learned that she had received a letter in an envelope with something granular rattling inside. She opened the letter, which contained a vague death threat and was signed, “This is KC and I approve this message.” She didn’t let the mysterious material fall out of the letter, and she washed her hands carefully, she said. She felt no ill effects, but the grainy material was ricin, authorities later determined.

The federal investigation initially focused on Curtis, who also had a connection to Holland. She sentenced him to six months in jail for a 2003 assault on a Tupelo lawyer, according to court documents. Curtis had also been hired by Wicker to perform at a party in his Elvis persona.

The language in the letters — including the two intercepted in Washington before they could reach the White House or the Senate — was similar to that used by Curtis in his posts on Facebook and other online forums. The letters also made reference to a novel Curtis is writing that details his theory that there is a vast black market in human body parts.

But after Curtis was arrested last week, his attorney said he was being set up. Authorities eventually decided that was correct.

On Tuesday, when Curtis walked out of jail a free man, law enforcement officials, speaking on the condition of anonymity, said they believed he was being framed.

Enter Dutschke. He and Curtis have a fraught history, seemingly played out almost entirely online. After Curtis was released from custody last week, he said he and Dutschke had had a falling-out and that Curtis had challenged Dutschke to a fight that never occurred.

According to acquaintances, Curtis believed that Dutschke had reneged on an offer to help him publish an article about the alleged conspiracy to sell human body parts.

Dutschke said last week that he and Curtis had gotten into a dispute a few years ago when Curtis claimed to be a member of Mensa, the club for people with high IQs. Dutschke asked Curtis to remove that claim from his Facebook page and threatened to sue him if he didn’t.

Dutschke expressed consternation that he was being looked at as a suspect in the ricin case. “I feel like he’s getting away with the perfect crime,” Dutschke said of Curtis in a phone interview last week with the Jackson Clarion Ledger, a Mississippi newspaper.

Dutschke went into hiding on Thursday to escape the media attention. The FBI and local law enforcement officials spent five hours hunting for him before his attorney revealed her client’s location. Agents spent more than 10 hours earlier in the week searching his home and continued the search at a martial-arts studio, Tupelo Taekwondo Plus, that Dutschke had been operating. The studio closed in January when Dutschke became the target of a child-molestation investigation.

A grand jury indicted him this month. The alleged victim is a 7-year-old girl who had visited his studio, his attorney, Basham, said. Dutschke has denied sexual contact with the girl.

Though the ricin case seems to have emerged from a small-time feud between a couple of eccentrics, the government response has been robust. Among the government agencies that joined the FBI in the investigation were the Secret Service, the U.S. Postal Inspection Service, the Capitol Police, the counterterrorism section of the Justice Department’s national security division, the Mississippi National Guard, the Mississippi Office of Homeland Security and multiple county and city law enforcement units.

Dutschke is scheduled to appear Monday in federal court in Oxford.

Alice Crites and Julie Tate contributed to this report.

Discuss this topic and other political issues in the politics discussion forums.