Hours after a suspect being held in connection with sending a ricin-laced letter to Sen. Roger Wicker, R-Miss., was released from custody, federal prosecutors moved to dismiss the case against him entirely.

The news also comes just days after Capitol Hill law enforcement officials informed the congressional community that it was safe from further mail attacks.

The evidence against, Paul Kevin Curtis a Corinth, Miss. resident, once appeared all but stacked against him: He had a history of displaying behavior that pointed to psychological disturbances and, in his capacity as an Elvis impersonator, was once invited to perform at a party Wicker was throwing for friends.

But a comprehensive sweep of his home showed no traces of ricin or of ingredients needed to make the poisonous substance. A search of his computers also indicated he had not done any research on the Web about how to make ricin.

At a news conference on the steps of the Oxford, Miss., courthouse on Tuesday evening, Curtis’ attorney, Christi McCoy, said she was “thrilled” with the news that the U.S. attorney’s office had moved to dismiss the case without prejudice.

“We have had nothing but professionalism throughout, and I think that needs to be said,” McCoy said in regard to the federal authorities’ treatment of her client over the past week. “They led with evidence they had at the time and realized it was a dead end and then they went to where the evidence was.”

Curtis, wearing sunglasses and a suit on loan from his brother, thanked Jesus Christ for his ultimate vindication at the news conference. He also thanked Wicker for “all the kind words about me in the press. … I have always felt he was a good and honest man.”

Law enforcement officers are pursuing leads that Curtis might have been framed by an acquaintance named J. Everett Dutschke, a Tupelo, Miss., resident with whom Curtis has an adversarial relationship and whose home has been subject to search by federal agents since earlier Tuesday.

A taekwondo studio proprietor, Dutschke has faced previous allegations of child molestation and at one time ran for a seat in the Mississippi House of Representatives on the Republican ticket. If he is behind the contaminated mailings, it might help explain why Lee County Judge Sadie Holland was targeted along with Wicker and President Barack Obama: She is the mother of Democratic Rep. Daniel Holland, whom Dutschke challenged in 2007.

One of Curtis’ lawyers has reportedly said that Dutschke may have framed Curtis in the case, but Dutschke has denied involvement.

Tuesday’s news was only the latest twist in a bizarre saga. A week ago, with Washington already on edge after the Boston Marathon bombings, news broke that the Senate mail-handling facility had intercepted an envelope bound for Wicker’s Capitol Hill office that tested positive for ricin.

The news that a suspect is still at large comes after staffers and members generally felt calmer after receiving assurances from the law enforcement community that a prime suspect had been apprehended.

Capitol Police Chief Kim Dine’s and Senate Sergeant-at-Arms Terrance Gainer praised their officers and investigators, whom they credited with taking the lead in Curtis’ arrest.

Capitol Police spokesman Shennell Antrobus declined to comment, while Gainer said that Curtis’ release didn’t change the fact that members, staffers and visitors of Capitol Hill have been safe all along.

“Our Capitol community should be aware that all mail is being screened, as it was when our mail technicians intercepted the first letter before it ever reach[ed] the Senator,” Gainer wrote in an email to CQ Roll Call. “They should not feel at risk, we have their backs.”

The Curtis news also coincided with Senate Majority Leader Harry Reid telling reporters on Tuesday that potential ricin was discovered in the Washington, D.C., area at Joint Base Anacostia-Bolling, the Defense Intelligence Agency.

Later Tuesday, Lt. Col. Thomas F. Veale, a DIA spokesman, said that the base may have had a false alarm, noting that no suspicious packages or envelopes were found in a search of the facility.

John Donnelly contributed to this report.