HOLLYWOOD, Fla. – A serial killer who died more than a decade ago is the person who decapitated the 6-year-old son of “America’s Most Wanted” host John Walsh in 1981, police in Florida said Tuesday.

The announcement brought to a close a case that has vexed the Walsh family for almost three decades, launched the television show about the nation’s most notorious criminals and inspired changes in how authorities search for missing children.

“Who could take a 6-year-old and murder and decapitate him? Who?” an emotional John Walsh said at Tuesday’s news conference. “We needed to know. We needed to know. And today we know. The not knowing has been a torture, but that journey’s over.”

Police named Ottis Toole, saying he was long the prime suspect in the case and that they had conclusively linked him to the killing. They declined to be specific about their evidence and did not note any DNA proof of the crime, but said an extensive review of the case file pointed only to Toole, as John Walsh long contended.

“Our agency has devoted an inordinate amount of time seeking leads to other potential perpetrators rather than emphasizing Ottis Toole as our primary suspect,” said Hollywood Police Chief Chadwick Wagner, who launched a fresh review of the case after taking over the department last year. “Ottis Toole has continued to be our only real suspect.”

Toole had twice confessed to killing the child, but later recanted. He claimed responsibility for hundreds of murders, but police determined most of the confessions were lies. Toole’s niece told the boy’s father, John Walsh, her uncle confessed on his deathbed in prison that he killed Adam.

Wagner acknowledged numerous missteps in the investigation and apologized to the Walshes.

“I have no doubt,” John Walsh said. “I’ve never had any doubt.”

Many names have been mentioned in connection to the case in the years since the killing, including serial killer Jeffrey Dahmer, but Toole’s has persistently nagged detectives. John Walsh has long said he believed the drifter was responsible, saying investigators found at Toole’s home in Jacksonville a pair of green shorts and a sandal similar to what Adam was wearing.

Toole died of cirrhosis in prison in 1996 at the age of 49. He was serving five life sentences for murders unrelated to Adam Walsh’s death.

Adam Walsh went missing from a Hollywood mall on July 27, 1981. Fishermen discovered his severed head in a canal 120 miles away two weeks later. The rest of his body was never found.

Authorities made a series of crucial errors, losing the bloodstained carpeting in Toole’s car – preventing DNA testing – and the car itself. It was a week after the boy’s disappearance before the FBI got involved.

For all that went wrong in the probe, the case contributed to massive advances in police searches for missing youngsters and a notable shift in the view parents and children hold of the world.

Adam’s death, and his father’s activism on his behalf, helped put faces on milk cartons, shopping bags and mailbox flyers, started fingerprinting programs and increased security at schools and stores. It spurred the creation of missing persons units at every large police department.

The case also prompted national legislation to create a national database and toll-free line devoted to missing children, and led to the start of “America’s Most Wanted,” which brought those cases into millions of homes.