The detectives would arrive soon, so Thomas Klaber made deli sandwiches and coffee at his Cleveland home as he wondered what new information they had about the killing of his younger sister more than four decades ago.
Detective Coy Cox of the Boone County Sheriff’s Office in Kentucky pulled up a chair.
“We have the ultimate answer in the case, and we’re going to share that with you,” the detective recalled telling Mr. Klaber. “I’ll tell you as little or as much as you want to know.”
Mr. Klaber, who had volunteered in June 1976 to identify the body of his 16-year-old sister, Carol Sue Klaber — a moment that has tortured him ever since — did not hesitate.
“I want to hear it,” he said.
On Wednesday, about a week after informing Mr. Klaber, the sheriff’s office announced that it had solved a cold case that had thrust the Klaber family into a decades-long tangle of mystery and frustration after Ms. Klaber was sexually assaulted and killed in Kentucky in 1976.
Her body was found on June 5 that year in Walton, Ky., about 60 miles north of Lexington. Investigators had scoured the grassy hills of Boone County, which borders the Ohio River, for clues.
Through DNA evidence, the sheriff’s office concluded that Thomas W. Dunaway, who was then 19, had killed Ms. Klaber.
At the time, Mr. Dunaway had been living in Park Hills, Ky., where Ms. Klaber, who played the violin and loved her acoustic guitar, was last seen getting into a car, possibly a gray Chevrolet or Pontiac Grand Prix, Detective Cox said. It was possible that Mr. Dunaway and Ms. Klaber knew each other in the neighborhood, he said.
Mr. Klaber, a retired bass trombonist for the Cleveland Orchestra, took a deep breath when he heard the news.
“When he exhaled, you could see, physically, his body just kind of settle into it,” Detective Cox said.
Still, there was a lingering sense of anger for Mr. Klaber when he learned that Mr. Dunaway had died in 1990 at the age of 33.
That meant no formal charges. No trial. No chance to sit in a courtroom and look at the man responsible for his sister’s killing.
“I wish I had known in 1990. What do you say after all this time?” Mr. Klaber said, adding, “I had some rather un-Christian plans for him.”
While the answers brought some relief, he said he had a new thorny question to reckon with: What does justice mean now?
One former detective with the Boone County Sheriff’s Office, Jerry Keith, had obsessively tried to bring the investigation to a close years ago. He had a copy of the case report at his home.
“He literally carried this case with him his whole life,” Detective Cox said.
Before his death in September 2017, Mr. Keith had developed theories that pointed to two possible assailants. That same year, the sheriff’s office established its cold case unit, staffed by Detective Cox and Detective Tim Adams, and together they pursued Mr. Keith’s theories.
In the end, the killer was neither of the possible assailants Mr. Keith had considered, but Detective Cox said he was grateful to the former detective because “in cases, a lot of times, you have to prove who didn’t do it to get to who did.”
The detectives sent DNA left by the killer on the victim to a lab to be tested through genetic genealogy, the process in which DNA samples are used to find relatives of suspects, which in this case was Mr. Dunaway. Detectives traveled to meet a child of Mr. Dunaway’s — who had never really known their father — to collect DNA.
“They were shocked,” Detective Cox said of the child, who was not identified.
The detectives then learned more about Mr. Dunaway’s past: He had killed another person, Ron Townsend, in Northern Kentucky in December 1976 — just months after Ms. Klaber was killed — and served more than seven years in prison for that crime.
He had also enlisted in the U.S. Army days after Ms. Klaber’s body was found. On Christmas Eve of that year, he had been arrested in South Carolina for burning a Chevrolet Impala and illegally possessing a sawed-off shotgun.
On March 1, Mr. Klaber sat in his chair, taking in all the investigative findings.
The case had traumatized his family, including his older brother, and he had long wondered why he hadn’t sought therapy after seeing what the killer had done to his sister.
He said that sight had left him with “a vague darkness somewhere down inside me.”
His son, Daniel Klaber, 28, said that when he was out late with friends, his father would frantically call several times and plead: “It’s been too long. Call me. Where are you?”
“Whenever someone was overdue, I would start not just worrying, but, you know, I was expecting this to happen again,” the senior Mr. Klaber said.
This month, as he processed the news from the detectives, he realized that one small detail gave him comfort.
All his life, he had worried about investigators potentially exhuming his sister to collect DNA. Detective Cox told him that, in the end, it was Mr. Dunaway’s body that had been exhumed for that reason.
“There’s a little bit of justice,” Mr. Klaber said. “You’re going to disturb somebody’s remains? Dig him up.”