McCullough was convicted in September 2012 of kidnapping and killing a 7-year-old girl in Sycamore, Illinois, 55 years earlier.
Friday's filing by The Exoneration Project
, a legal clinic at the University of Chicago Law School, takes apart the case built against McCullough -- including eyewitness identification, a timeline of events and the testimony of jailhouse informants.
With their filing, McCullough's attorneys also raised the specter of possible police and prosecutorial misconduct.
"There are serious issues with all of this evidence," the filing states.
Russell Ainsworth, one of McCullough's lawyers with The Exoneration Project, elaborated in an interview that investigators and prosecutors believed they'd solved "a one in a million case." But when the facts didn't add up, he added, "the authorities started to put their thumb on the scale to implicate Jack in this crime. But Jack is innocent, and that's not fair."
A spokesman for the Illinois State Police, which led the investigation of McCullough, said he could not comment because the matter is in litigation.
A hearing on the motion to declare McCullough innocent is set for Thursday in Sycamore, a small town about 70 miles west of Chicago.
It's where McCullough grew up in a small, boxy house around the corner from Maria Ridulph; he was 18 and she was 7 when she vanished while playing in the snow with a friend on the evening of December 3, 1957.
Court documents assert that there is no way McCullough could have abducted and killed Maria because he was 40 miles away in Rockford, Illinois, trying to enlist in the US Air Force when she disappeared.
His alibi was reinforced by phone records verifying a collect call he said he made to his family's Sycamore home from a pay phone at the Rockford post office. The call was placed at 6:57 p.m., within a few minutes of the time the FBI believed Maria was taken.
Just as State's Attorney Richard Schmack did before them, McCullough's Exoneration Project lawyers raised troubling questions about whether the original prosecution team manipulated the timeline, cut testimony deals with inmates and ignored or buried details that pointed to McCullough's innocence.
Schmack, whose report led to McCullough's release, said the filing was expected. He plans to file a brief response.
After Maria disappeared, nearly three dozen FBI agents descended on Sycamore and interviewed hundreds of people, including McCullough and his parents. FBI chief J. Edgar Hoover took a personal interest in the case, as did President Dwight Eisenhower.
Maria's body was found some 120 miles west of Sycamore in April 1958. For years, the search for her killer went nowhere -- until one of McCullough's sisters emailed an Illinois State Police tip line in the fall of 2008.
Janet Tessier told police that her mother had claimed on her deathbed that she knew the killer's identity: her son, John Tessier, who later changed his name to Jack McCullough.
The McCullough investigation began in late 2008. Documents obtained by CNN through a public records request revealed that police and prosecutors did not receive the FBI's reports from 1957-58 until June 3, 2010 -- nearly two years into their investigation. And then prosecutors fought to keep the contents of those reports -- including McCullough's alibi and the fact that the FBI had cleared him -- out of his murder trial.
"Jack McCullough is an innocent man who was victimized by the judicial system," said Ainsworth, who has gone to court on behalf of several clients who were wrongfully convicted. "You have detectives who picked their perpetrator before they looked at all the facts, and then they tried to make the facts fit their perpetrator. They turned everything on its head."
In particular, The Exoneration Project's lawyers contend that investigators buried evidence about the Rockford pay phone that supported McCullough's alibi.
Illinois State Police investigators obtained records from the current owner of the old Rockford Post Office building, the court document alleges. But even afterward, they continued to assert that they didn't know the pay phone's number and suggested the call could have been made from anywhere, the filing alleges.
"ISP investigators knew that there was a pay phone in the Rockford Post Office in 1957 and were provided a number for that pay phone which matched the number from which McCullough placed that 6:57 p.m. call on December 3, 1957, establishing an airtight alibi for Mr. McCullough, but (they) chose to ignore this evidence, even excluding it from their reports, because it did not fit their theory of the crime," the court documents say.
Line up the usual suspects?
In addition, Exoneration Project lawyers took aim at the photo lineup at the heart of the case against McCullough.
The night Maria disappeared, she had been playing at a street corner with her childhood friend, Kathy Sigman Chapman, when a man approached. He gave his name as Johnny and took Maria on a piggyback ride. Chapman, then 8, went home to get her mittens. When she returned, Johnny -- and Maria -- were gone.
Five decades later, investigators showed Chapman a photo lineup of six men, including McCullough. She pointed to McCullough's picture and said he was Johnny.
McCullough's lawyers say the 2010 lineup was suggestive, and they question whether an 8-year-old could really remember the face of a man she spoke with for a few minutes 52 years earlier. They were outside, it was snowing, and there was no streetlight at the corner.
"Even a very confident and well-intentioned eyewitness can misremember and misreport the events of a crime scene and who was involved," expert Nancy Steblay wrote in a 20-page report prepared for McCullough's lawyers and filed with the court. "Memory is not like a video recorder. Instead, our memory of an event or a person is very malleable and is often unreliable."
Steblay pointed to 35 years of studies that show a one-in-three chance a lineup will produce a false identification if the real suspect isn't shown. People want to help, and their brains try to fill in the blanks; instead of recognition, a person being shown a lineup is far more likely to try to match a photograph with an image stored in their memory.
A child's perception, cognitive development and desire to please adults further complicates matters, Steblay's report stated.
At McCullough's trial, Chapman testified she'd been shown hundreds, maybe thousands of photographs of suspects in the weeks and months after Maria's disappearance. Each time she was, her memory was corrupted, Steblay said in her report.
In December 1957, Chapman falsely identified a "filler" as the suspect in a lineup held in Madison, Wisconsin. And she said another suspect in another lineup seemed similar to "Johnny." On the witness stand, she did not recall those events, and so the defense wasn't able to ask more questions about that misidentification.
By then, Steblay said, Chapman's memory and any identification she made could already be considered unreliable. The passage of 52 years only dimmed her memory further.
Steblay and McCullough's lawyers cite additional issues with the 2010 lineup's presentation. The investigator who showed the photos to Chapman knew the suspect's identity, now a violation of widely accepted practices. In fact, a law went into effect in Illinois in January 2015 requiring "blind" live and photo lineups -- meaning the person administering them can't know the identity of the actual suspect.
Steblay had other issues with the lineup, which she called "biased against the defendant." The other five "filler" suspects were shown in high school yearbook photos, but McCullough had dropped out, so another photo of him was used. In effect, Steblay concluded, the presentation made him stand out, increasing the risk of a false identification.
"The identification procedure in this case was so suggestive (and late in its timing) as to undermine the reliability of witness memory and to create the strong likelihood of misidentification," Steblay concluded.
Schmack said he found the science in Steblay's report "fascinating," adding that he will advise the felony attorneys in his office to read it.
Former prosecutors Clay Campbell and Julie Trevarthen did not immediately respond to CNN's request for comment, and have not commented in the recent past. Chapman's husband, Mike, said she would not be commenting.
Charles Ridulph, Maria's brother and a church deacon in Sycamore, said in an emailed statement to CNN that he still believes in McCullough's guilt and that his release was a miscarriage of justice.
"This has been a horrible ordeal," he said in the statement. "It has gone beyond any concept of what our justice system is intended to represent. But, Jesus said, 'In this world you will have trouble. But take heart! I have overcome the world.' Heaven knows that we have seen trouble."
Since McCullough's release, two inmates who testified about jailhouse conversations with him have filed federal lawsuits
against police and prosecutors, saying they failed to uphold their end of deals they made for the testimony. A third inmate was deported.
The informants' testimony, along with Chapman's eyewitness identification, were the two main pillars Judge James Hallock cited in finding McCullough guilty.
A few weeks after McCullough's murder conviction, Schmack was elected state's attorney. He reviewed the 4,500-page file as McCullough's case moved through the appellate courts.
Schmack sought out additional evidence, including subpoenaing AT&T for old phone records, and concluded McCullough's alibi held up and that the FBI got it right in 1957.
Schmack's report to the court led to McCullough's freedom. It was included in The Exoneration Project's filing, with McCullough's lawyers picking up where the prosecutor left off.
McCullough wants a finding of innocence not just to remove the possibility of a retrial; he also needs it to qualify for state compensation, counseling and job training, as well as unemployment benefits and back Social Security payments.
"The maximum amount of compensation available to Mr. McCullough is relatively small given the magnitude of his loss, but significant for a man who left prison with very few assets to his name," the court papers say.
McCullough told CNN he was so broke when he returned home that he and his wife lived for a few weeks on canned goods purchased before his 2011 arrest.
McCullough, the lawyers said, was able to have his conviction overturned and the charges dismissed "due to his steadfast determination to prove his innocence and an exhaustive FBI investigation in 1957 and 1958 that proves that innocence."
And now, the court papers say, he's asking a judge to officially declare him innocent of the Maria Ridulph murder "so he can move on with his life and leave this conviction and its terrible consequences behind him."