Tammy Anderson, 57, felt unnerved as four Indiana State Police troopers arrived at her apartment on Tuesday to arrest her husband, who never liked to talk much about his past.
Ms. Anderson’s husband, Ronald J. Anderson, 61, of Seymour, Ind., was being charged with murder, the troopers said, in connection with the 1982 killing of Clifford Smith, 24, who was Mr. Anderson’s brother-in-law.
As the troopers took her husband away in handcuffs, Ms. Anderson said in an interview on Wednesday, she felt indignant.
“I don’t know anything about this,” Ms. Anderson said, though she emphasized that she believed her husband was innocent.
Relatives of Mr. Smith said in interviews that they had long accused Mr. Anderson of being the culprit, even as an exact motive remained unclear for decades. The arrest, exactly 41 years after Mr. Smith was fatally shot in the head on Halloween in 1982 in Jackson County, in southern Indiana, has again raised tensions among the Smith family and Mr. Anderson’s relatives in a cold case that has long brewed bitterness and suspicion.
The arrest has also supported a secret belief that had festered for more than four decades within the Smith siblings’ households: A brother-in-law known for having a hot temper and taking psychedelic drugs had killed their shaggy-haired relative, they believed, and no detective could turn that inkling into an arrest warrant.
Sgt. Stephen Wheeles of the Indiana State Police said by phone on Wednesday that the authorities could not share many details about how they had pinpointed Mr. Anderson as the suspect or why it had taken so long. But interviews with family members, including with a sister of Mr. Anderson and Mr. Smith’s widow, Joyce Dyer, had progressed their investigation, he said.
Other key details also led the police to Mr. Anderson, the sergeant said: Mr. Anderson had retrieved a loaded shotgun from a house on East 13th Street in Seymour, Ind., on Oct. 30, 1982, left the home in a vehicle with Mr. Smith and then returned the weapon to the house.
Mr. Smith was not seen alive again after he and Mr. Anderson left the home on East 13th Street, Sergeant Wheeles said. Investigators found that Mr. Anderson had returned to the crime scene after the killing to “hide potential evidence,” the sergeant added.
About a month after Mr. Smith was reported missing, his body was found on Dec. 1, 1982, by two animal trappers who were walking near a bayou close to the White River, about two miles north of Seymour, according to an affidavit.
Lonnie Smith, Mr. Smith’s eldest brother, said that he vividly remembered how dumbfounded he felt on the day his brother’s body was retrieved.
“I didn’t know which way to go,” he said. “I just lost everything.”
Clifford Smith, who was one of seven children and loved baseball, had been known as a daredevil and a competitive young man in his small hometown, Columbus, Ind., where he would jump dirt trenches with his bicycle as a teenager before growing up and quickly falling in love with a woman named Joyce.
They married in the spring of 1982.
Lonnie Smith, 67, and his younger brother, Leonard Smith, 63, said in interviews this week that their brother’s wife, who later remarried, had told them in the 1980s that she believed her brother had killed Mr. Smith.
Ms. Anderson, too, said that she had heard Ms. Dyer express this belief.
“She would say, ‘Your husband is the one who killed my husband,’” Ms. Anderson recalled.
Ms. Anderson added that if her husband “did do it, he did it to protect her because Clifford beat on her all the time.”
When asked in a brief phone interview who she thought had killed her ex-husband, Ms. Dyer said, “I don’t know who done it.” She added: “I wasn’t there. I didn’t see anybody do it.”
Mr. Smith’s brothers said that while he and Ms. Dyer may have had disagreements, Mr. Smith was not a hostile drunk who beat his wife.
In the affidavit filed last week, Ms. Dyer’s stance on who had killed Mr. Smith seems more definitive.
The affidavit states that both Ms. Dyer and Mr. Anderson acknowledged that they had not told the truth in interviews with investigators and that Ms. Dyer eventually gave a statement that “implicated Ronald as the person who killed Clifford.”
The affidavit also describes a possible motive.
Ms. Dyer told investigators that on the night of Oct. 30, 1982, she was alone at someone else’s house when her brother and husband “showed up with some stolen items” that she wanted nothing to do with, the affidavit states.
Mr. Smith tried to get Ms. Dyer to go home with him, but Ms. Dyer did not want to because he was drunk, the affidavit states.
Ms. Dyer then became angry and said, “I wish someone would blow your head off,” according to the document. Mr. Anderson told Ms. Dyer that Mr. Smith had been responsible for the burglary and that Mr. Smith had been “hitting him all day.”
Mr. Anderson then walked to a corner of a room, where a shotgun sat. He loaded it with four red shells, the affidavit states, and made a threat: “If he keeps hitting me,” Mr. Anderson said, referring to Mr. Smith, “I’ll kill him.”
Mr. Smith later struck Mr. Anderson twice on the shoulder and walked down a street. He was later picked up in a car by Mr. Anderson, court documents state.
It took four days for Ms. Dyer to report her husband missing, officials said. She filed for divorce on Nov. 17, 1982, while the search for him continued, Mr. Smith’s relatives said.
Ms. Dyer did not return follow-up calls seeking additional comment on Wednesday.
Sergeant Wheeles said that the troopers decided to arrest Mr. Anderson on the exact anniversary of the killing to give the date a new significance for the victim’s family.
Lonnie Smith said on Wednesday that he was planning to drive to his brother’s gravesite. There, he said, he would kneel down, touch his sibling’s cold, gray tombstone and say: “Brother, I’m here. We got him.”
Kitty Bennett contributed research.