HLN’s “How It Really Happened with Hill Harper” returns for its fifth season with a comprehensive look at the Atlanta child murders. Watch the two-hour premiere on Sunday, August 23 at 9 p.m. ET/PT.

CNN  — 

For decades, Catherine Leach has never accepted the official explanation about who was behind the series of killings in Atlanta that terrorized the city and left her teenage son dead.

Her 13-year-old son, Curtis Walker, was one of 29 mostly black children who were killed from 1979 to 1981 in a spate of crimes that became known as the Atlanta child murders. During those tense three years, children vanished, only to have their bodies turn up days later, with many of them having been strangled. The killings haunted Atlanta and brought grief to families, but also festered racial suspicions.

Leach felt the investigation didn’t go far because of the children’s race. Some wondered why the killings of black kids didn’t draw the national outrage that usually accompanies reports of missing and slain children.

Almost 40 years later, Leach and many of the victims’ families are skeptical that Wayne Williams, the man who was implicated as the prime suspect in the slayings, was the culprit.

Atlanta authorities announced on Thursday that they, along with state and county officials, would review the evidence from 29 cases. The point is not to vindicate Williams, but to provide closure to the families of victims who have long sought answers about their children’s killers, said Atlanta Mayor Keisha Lance Bottoms.

Bottoms recently spoke to Atlanta Police Chief Erika Shields, she said, to see if there is any evidence that could be re-examined “that may give some peace – to the extent that peace can be had in a situation like this – to the victims’ families.”

It’s an effort Leach supports.

“It seems like the Atlanta missing and murdered children have, have been forgotten in this city. They have been forgotten. And I don’t know why,” Leach said.

Leach said she doesn’t believe Williams was the culprit behind the Atlanta Child Murders and that he was a “scapegoat.”

“They had to do something for us, to cool this place down to … pacify the parents,” she said.

Though the Atlanta Police Department declared Williams was responsible for most of the children’s killings, he was not charged in the youngsters’ slayings, but in the murders of Nathaniel Cater and Jimmy Ray Payne, adults whose bodies were found in a river. Williams is serving a life sentence after being found guilty of both killings in 1982.

Leach and other families have said they believe the Ku Klux Klan, not Williams, was behind the serial killings. Leach’s reasoning is that nobody else would want to kill little black kids.

It’s a belief shared by Larry Platt, whose cousin Lubie Geter was killed at age 10. Platt said he believes it was the KKK. “The person who did this is still walking,” Platt said.

Such speculations and theories circulated during the time of the killings, said Danny Agan, a detective who handled three of the cases.

“The KKK being the blame agent on this is something that goes back to at the time of the murders,” he said. “There was speculation within the community.”

Years after Williams’ arrest, it was revealed that authorities had investigated the KKK as part of the probe into the killings.

Agan said that 80% of the children who were killed are connected to Williams through fiber evidence.

“There’s a lot of people who want to deny the truth or the facts regardless of what they are,” Agan said. But he added that there’s no harm in seeking the truth through re-examining the cases.

Williams has insisted that he is innocent. He told CNN in a 2010 documentary that Atlanta was “in a panic” over the killings and was bent on convicting a black man because arresting a white man might have sparked a race war and “Atlanta would’ve gone up in flames.”

“That fiber evidence may well have been manipulated in this case, point blank and simple, simply because they had a suspect – it was Wayne – and that manipulation no doubt has continued even after my trial and up until this point,” Williams said.

Atlanta Police, Fulton County and the Georgia Bureau of Investigation will examine never-before-analyzed evidence and re-examine others in the case, though officials did not promise any outcomes that would change the 40-year-old narrative.

CNN’s Eliott C. McLaughlin contributed to this report.