TUPELO, Mississippi (AP) -- Law enforcement officials searched the home of a second man in connection to ricin-laced letters sent to President Barack Obama and a U.S. senator after charges were dropped without explanation against a man arrested in the case last week.

Everett Dutschke, whose home was searched Tuesday by dozens of officials, some in hazmat suits, had feuded with Paul Kevin Curtis, a 45-year-old celebrity impersonator who had maintained his innocence since his arrest.

The search began early Tuesday afternoon and ended about 11 p.m. CDT, with officials declining to comment on what they had found or on the next phase of the investigation.

At one point, two FBI agents and two members of the state's chemical response team left Dutschke's property and began combing through ditches, culverts and woods about a block away from his house in the neighborhood of single-family detached homes.

Dutschke, who spoke with The Associated Press by telephone during the search, said his house was also searched last week.

"I don't know how much more of this I can take," he said.

No charges have been filed against Dutschke and he hasn't been arrested. Both he and Curtis, who had faced charges in the case, say they have no idea how to make the poisonous ricin and had nothing to do with sending the letters to President Barack Obama, U.S. Sen. Roger Wicker of Mississippi and a state judge.

A one-sentence document filed by federal prosecutors said charges against Curtis were dropped, but left open the possibility they could be reinstated if authorities found more to prove their case. Prosecutors were not immediately available for comment.

Dutschke and Judge Holland know each other: In 2007, he lost his Republican bid for a seat in the Mississippi House of Representatives to Holland's son, Democratic state Rep. Steve Holland, who was the incumbent.

Since Curtis' arrest at his Corinth home on April 17, his attorneys have said their client didn't do it and suggested he was framed. An FBI agent testified in court this week that no evidence of ricin was found in searches of Curtis' home.

The dismissal is the latest twist in a case that has been strange from the beginning and rattled the country during the same week as the Boston Marathon bombing and a fertilizer plant explosion in West, Texas.

Dutschke and Curtis are no strangers to each other. Dutschke said the two had a disagreement and the last contact they had was in 2010. Dutschke said he threatened to sue Curtis for saying he was a member of Mensa, a group for people with high IQs.

Hal Neilson, an attorney for Curtis, said the defense gave authorities a list of people who may have had a reason to hurt Curtis.

"Dutschke came up," he said. "They (prosecutors) took it and ran with it. I could not tell you if he's the man or he's not the man, but there was something there they wanted to look into."

An FBI intelligence bulletin obtained by the AP said the two ricin-laced letters addressed to Obama and Wicker said: "To see a wrong and not expose it, is to become a silent partner to its continuance." Both were signed, "I am KC and I approve this message."

Curtis was already well known to Wicker because he had written to the Republican senator and other officials. Curtis also wrote a novel called "Missing Pieces," about black-market body parts he claimed to have found while working at a hospital _ a claim the hospital says is untrue. Curtis posted similar language on his Facebook page and elsewhere. The documents indicate Curtis had been distrustful of the government for years. He told the AP on Tuesday that he realizes his writings made him an easy target.

Multiple online posts under the name Kevin Curtis on various websites that could be seen by anyone refer to the conspiracy he claimed to uncover when working at a local hospital from 1998 to 2000. In one post, Curtis said he sent letters to Wicker and other politicians. He signed off: "This is Kevin Curtis & I approve this message."

Christi McCoy, another attorney for Curtis, said she doesn't know what new information prosecutors have, but said the plot to frame her client was "very, very diabolical."

Curtis, dressed after his release Tuesday in a black suit, red shirt, necktie and sunglasses, said he met Dutschke in 2005 but that for some reason Dutschke "hated" and "stalked" him. "To this day I have no clue of why he hates me."

Ricin is derived from the castor plant that makes castor oil. There is no antidote and it is at its deadliest when inhaled. It can be aerosolized, released into the air and inhaled. The Homeland Security handbook says the amount of ricin that fits on the head of a pin is enough to kill an adult if properly prepared.

Dutschke said agents asked him about Curtis, whether Dutschke would take a lie-detector test and if he had ever bought castor beans, which can be used to make the potent poison.

"I'm a patriotic American. I don't have any grudges against anybody. I did not send the letters," said Dutschke, who was a Republican candidate for the Mississippi House of Representatives in 2007 but lost.

After charges were dropped against Curtis, he said: "I'm a little shocked."

Dutschke said his attorney wasn't with him and he didn't know whether he was going to be arrested.

Tuesday's events began when the third day of a preliminary and detention hearing for Curtis was canceled without officials explaining the change. Within two hours, Curtis had been released, though it wasn't clear why at first.

FBI Agent Brandon Grant said in court Monday that searches last week of Curtis' vehicle and house in Corinth found no ricin, ingredients for the poison, or devices used to make it. A search of Curtis' computers found no evidence he researched making ricin. Authorities produced no other physical evidence at the hearings tying Curtis to the letters.

All the envelopes and stamps were self-adhesive, Grant said Monday, meaning they won't yield DNA evidence. One fingerprint was found on the letter sent to a Lee County judge, but the FBI doesn't know who it belongs to, Grant said.