How do you get away with admitting there’s enough evidence to convict you for murder while maintaining your innocence?

You find a scapegoat.

In the case of Michael Peterson, that scapegoat is the entire criminal justice system. Peterson was convicted in 2003 of killing his wife, Kathleen, on December 9, 2001. That conviction was overturned in December 2011 after a judge ruled that a key witness—former State Bureau of Investigation agent Duane Deaver—had misled the jury about his findings. Peterson won a new trial and was poised to take the stand again in May. On Wednesday, his attorney filed a document detailing why Peterson is entering an Alford plea, accepting the ramifications of a guilty verdict while insisting “he is not responsible for [Kathleen Peterson’s] death in any way.”

In a memorandum supporting the plea, defense attorney David S. Rudolf seeks to discredit those whose testimony landed Peterson behind bars, painting Deaver as the mastermind—or at least the delusional architect—of the conspiracy.

A new trial would only produce the same results as the first, Rudolf argues, because evidence was compromised, and Kathleen Peterson’s family was manipulated into believing she had been murdered by her husband.

The “most obvious, and most serious, misconduct” in the case was perpetrated by the “now discredited” Deaver, Rudolf says. Rudolf suggests that Deaver “or others acting under his direction or control” tampered with blood spatters at the scene and moved evidence to create a narrative that Peterson had tried to clean up the scene after murdering his wife. (At the 2003 trial, prosecutors argued that Michael Peterson was a frustrated bisexual bent on collecting his wife’s $1.5 million life insurance policy).

Deaver began working for the SBI in December 1985. He was fired on January 7, 2011, after an independent review showed he had misrepresented blood test results in thirty-four cases. (Later, the state Human Resources Commission ruled that Deaver had been wrongfully fired and he was awarded thirty months of back pay).

Deaver was hardly alone in his misconduct. His entire unit—the Bloodstain Pattern Analysis Unit—was suspended in 2010 after an investigation by The News & Observer found more than one hundred cases of misrepresented blood test results between 1986 and 2002.

Wednesday’s motion says that Deaver was the first person to inspect the clothing Peterson was wearing the night Kathleen died. The clothes were not photographed by crime-scene technician Dan George, according to Rudolf’s motion. Rudolf also points to photographs of blood spatters at the crime scene that appear to show tampering while the home was under police control. Footprints revealed by Luminol testing were never photographed, the document says.

Rudolf also casts doubt on the credibility of chief medical examiner Deborah Radisch, pointing to notes taken by an assistant district attorney indicating that Radisch was told to “back up from her findings” that Kathleen had died from blood loss, as opposed to blunt-force trauma to the head, as detailed in an autopsy report.

“This case began when Michael Peterson was 58 years old. He is now 73. But most importantly, what the events of the last 15 years have shown Mr. Peterson is that the criminal justice system cannot be trusted to do justice,” Rudolf writes. “Law enforcement officers, prosecutors and medical examiners do not necessarily search for the truth. Once they have adopted a theory of a person’s guilt, a theory in this case created by former SBI Agent Duane Deaver, they ignore evidence that is inconsistent with their theory and twist facts to support their theory.”

Additional reporting by Megan Howard.

Further information on Kathleen Pearson’s daughter Caitlin Atwater breaking her silence, Michael Peterson pleading guilty, and the timeline of the Peterson case