NEW YORK — A former taekwondo instructor was taken into custody by federal authorities in Mississippi early Saturday morning, accused of mailing letters containing the poison ricin to the president, a senator, and a local judge.
The arrest of J. Everett Dutschke, 41, in Tupelo, Miss., is the second in two weeks in connection with the letters.
An earlier suspect, an Elvis impersonator named Paul Kevin Curtis, also of Tupelo, was released after no evidence was found linking him to the letters; Curtis’s lawyer said during a hearing in federal court that Dutschke appeared to have framed Curtis.
Deborah Madden, a spokeswoman for the FBI in Jackson, Miss., said Dutschke had been arrested at his home around 12:50 a.m. Saturday. A law enforcement official in Tupelo said his arrest was uneventful.
‘‘He walked out and they took him into custody,’’ said Sergeant James Hood of the Tupelo Police Department.
A lawyer for Dutschke did not immediately return a message seeking comment Saturday.
The arrest is the latest chapter in a bizarre case that began during the tense week of the Boston Marathon bombing.
Authorities had said letters addressed to President Obama and Senator Roger Wicker, Republican of Mississippi, had been found containing a ‘‘suspicious granular substance’’ later determined to be ricin, a deadly poison. A similar letter with the substance was also sent to Judge Sadie Holland of the Lee County Justice Court.
The letters spoke of ‘‘Missing Pieces,’’ and were signed ‘‘I am KC and I approve this message,’’ both standard parts of e-mail messages sent to numerous public officials by Curtis, who had been on a one-man campaign for more than a decade to expose what he alleged was an illicit organ harvesting scheme at a Tupelo hospital.
Curtis was arrested on April 17 and while in custody, federal agents searched his home — even, according to Curtis’s stepfather, tearing up the bed and the ceiling — as well a former wife’s house, but found no evidence tying him to the letters.
Law enforcement officials said Saturday that the letters were carefully crafted to mimic Curtis’s characteristic phrasing and concerns. While they regretted having arrested a man they now consider to be innocent, they wanted to move quickly to stop the poisoned letters, one official said.
Curtis’s brother Jack said neither he nor other family members immediately dismissed the charges as false, given Kevin Curtis’s history of mental illness.
‘‘We could understand especially with the things that were tied to his initials,’’ he said. ‘‘I could see why somebody would think it was Kevin, but when they said President Obama I thought, ‘Somebody messed up because he likes Obama.’ ”
The family suggested to authorities that Kevin Curtis might have been framed, and Jack Curtis said he told authorities to look at Dutschke; on Monday, in a hearing in federal court, Curtis’s lawyer mentioned Dutschke by name.
Dutschke and Curtis had long feuded on topics including their music careers, membership in the MENSA society, and Dutschke’s unwillingness to publish his allegations about the hospital in a local newsletter.
Dutschke, a bright but often abrasive man who ran unsuccessfully for the state Legislature, was arrested earlier this year on charges that he molested three underage girls, one as young as 7. He pleaded not guilty to the charges this month.
On Tuesday, Curtis was released from prison and the charges against him were dropped.
At a news conference, Curtis said he did not blame federal authorities but added that ‘‘this past week has been a nightmare for me and my family.’’
On Tuesday and Wednesday, federal agents searched Dutschke’s home and his former taekwondo school, Tupelo Taekwondo Plus. James D. Moore, the prosecuting attorney for Lee County, said that evidence had been found but would not characterize the nature of it.
As he became the center of the investigation, Dutschke denied having anything to do with the ricin letters but tried to keep a low profile, to the point where authorities briefly lost track of him.
The events were not shocking to some who knew both men. ‘‘There’s been bad blood between those two for years,’’ said Moore, the prosecutor. Of their entanglement in this case, he added ‘‘Hindsight’s 20/20, but knowing these two guys I ain’t surprised.’’