Osborne Wade allegedly took a 6-year-old boy into a garage to molest him and stabbed him to death in 1992, authorities say.

For a few years, they say, Wade, 42, walked the earth free, while an innocent man rotted in prison for what happened.

But in May, Wade — locked up for failing to register as a convicted murderer who stabbed a man to death in 1994 — gave a videotaped confession to killing the boy, prosecutors say.

He wanted to do one more thing: apologize.

So Wade wrote letters to the family of Lindsey Murdock, the boy he killed, and to Mark Maxson, who spent more than two decades behind bars for a crime he didn’t commit, prosecutors said.

Representatives of the Murdock family and Maxson said they haven’t received letters yet.

“There could be no greater tragedy that I’ve seen in my 14 years on the bench,” Cook County Judge James Brown said at Wade’s bond hearing Wednesday, ordering him held without bail. “It’s beyond belief this kind of situation could happen.”

Wade told authorities he saw Lindsey in an alley on the Far South Side in the summer of 1992 and took him to an abandoned garage to molest him and stabbed him with a long object he found in the garage, Assistant Cook County State’s Attorney Ethan Holland said.

Wade was previously arrested in the Nov. 4, 1994 stabbing death of Joseph Stephens, who was 18. Wade pleaded guilty and was sentenced to 22 years in prison in April 1997, court records show.

On May 1, 1997, he unsuccessfully tried to withdraw his plea, saying, “I do not deny being the one who committed the fatal act, but I did not intend for death to be the result of my actions.”

“Petitioner suffered from mental illness as a result of his crime and associated with taking another’s life, one of whom was nearly a family member and had lived with petitioner,” he wrote.

Wade allegedly killed Lindsey about two years before he killed Stephens.

Lindsey was reported missing on Aug. 29, 1992. His strangled and stabbed body was found the next day under debris and near his clothes in the garage in the 10700 block of South State.

Lindsey Murdock was murdered in 1992. | Courtesy ABC7Chicago

Lindsey Murdock was murdered in 1992. | Courtesy ABC7Chicago

At the time, Maxson told a TV reporter he bought potato chips for Lindsey at a liquor store and told him to go home on the day the child disappeared.

Police interviewed Maxson and said they were suspicious of his changing stories. Police said he confessed that he sexually assaulted and killed the boy in the garage after smoking crack and drinking beer. Detective Cmdr. Robert Beavers said Maxson thought that “by being helpful he would throw us off his trail.”

At Maxson’s sentencing in 1994, Judge Daniel Locallo said Maxson possessed a “malignant heart” and needed to be removed from society, even though Maxson insisted he was innocent and no physical evidence linked him to the crime.

Maxson continued to claim that detectives punched and kicked him during their interrogations and that he was coerced into giving a confession. In 2013, the Illinois Torture Inquiry and Relief Commission found Maxson’s allegations were credible.

Mark Maxson after he was released from prison on Tuesday, Sept. 27. | Courtesy ABC7Chicago

Mark Maxson after he was released from prison on Tuesday, Sept. 27. | Courtesy ABC7Chicago

Recent DNA testing showed that the blood found on Lindsey’s clothes did not match the child’s or Maxson’s. The DNA profile was submitted to a law enforcement database last year and revealed a match to Wade, authorities say. Earlier this week, prosecutors asked Judge Thaddeus Wilson to vacate Maxson’s conviction. Maxson was released from Stateville Correctional Center on Tuesday.

On Wednesday, Brown told prosecutors he didn’t want a repeat of a man spending two decades in a “cage” for something he didn’t do. The judge said the circumstances surrounding the case were tragic, given that a “young, innocent” boy was murdered “savagely” and lost his life; a man lost 22 years of his life in prison, and now, a convicted murderer was being charged with the slaying.

Lindsey’s father, Lindsey Murdock Sr., said the news that authorities now believe Wade was his son’s killer is leaving him emotionally drained.

He said the FBI recently came to his home and showed him a photo lineup to see whether he could identify Wade, who had lived nearby in 1992. Murdock said he couldn’t pick Wade out because he never knew him.

“I am living it over and over again,” he said. “I was just horrified finding out my son died. I went to the morgue to identify my son’s body, and they told me what was done to him. I am thinking about it again 24 hours a day.”