California’s ban on the death penalty came to end in November, which has left Kevin Cooper facing execution– even though five judges have said that he might be innocent.

The 57-year-man was found guilty for a quadruple murder in 1983.  The Ninth Circuit, the top federal court in California, found that prosecutors illegally withheld information during Cooper’s trial that would have cast doubt on his guilt, but his conviction was not overturned. Now, in a last-minute effort to spare his life, Cooper will file an appeal to Gov. Jerry Brown.

“I am the only person in the history of the state to have five federal circuit judges say that ‘the state of California may be about to execute an innocent man,'” Cooper told NBC News.

In June of 1983, a family of four was found hacked to death. Douglas and Peggy Ryen, their 10-year-old daughter Jessica, and 10-year-old Chris Hughes were all found dead, but Josh, the Ryens’ 8-year-old-son, managed to survive despite the fact that his throat had been slit.

Initially, Ryen said that three white or Latino men had killed his family, and early physical evidence supported that theory. A local woman, Diana Roper, even contacted police to say that her estranged husband, Lee Furrow, was probably involved in the murders. She said that his hatchet was missing and that he had left coveralls covered in blood at her home the night of the murder.

However, when police picked up the bloodstained coveralls, they did not test them. The coveralls were thrown out entirely.

Instead, police suspected Cooper, who had recently escaped from prison and was hiding out in a house near the Ryens’. Authorities then gathered evidence against Cooper, including an eyewitness testimony and shoeprints that were later deemed suspect.

When Ryen saw Cooper’s arrest on TV, he at first said that Cooper was not the murderer. However, by the time the trial came around, he had changed his story and no longer said that his family had been killed by three white or Latino men.

Furthermore, police said that there were footprints on the scene that could only have been made by prison-issue shoes, despite the fact that Cooper’s own jail warden denied that this was the case.

On February 10, 2004, his scheduled execution was stopped at the last minute when the Ninth Circuit stepped in and called for a review of his case.

The case was reviewed again in 2009, and although the conviction was upheld, the case featured five judges who vehemently disagreed. “There is no way to say this politely,” the judges wrote. “The district court failed to provide Cooper a fair hearing and flouted our direction” on testing.

With true-crime shows like Netflix’s “Making A Murder” growing in popularity, controversial cases are under more public scrutiny.  Cooper’s story appeared in CNN Special “Death Row Stories” and he hopes people will believe in his innocence.

“I’m not asking America as a whole, or any one person in particular, to believe me. Forget what I say,” he told NBC News. “I’m asking people to believe those [judges],” he said.

“When I was convicted of burglary, I pled guilty to those,” Cooper said, “because I did them.”