Former Wisconsin state prosecutor Ken Kratz says Netflix’s Making a Murderer left out some key pieces of evidence against Steven Avery in its 10-part docu-series.

“You don’t want to muddy up a perfectly good conspiracy movie with what actually happened,” Kratz tells PEOPLE by email, “and certainly not provide the audience with the evidence the jury considered to reject that claim.”

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Filmed and produced over ten years, Making a Murderer examines the twist-filled case of Avery, a Wisconsin man who was released from prison after being exonerated for sexual assault only to be arrested again and convicted for the murder of a young photographer, Teresa Halbach.

Avery is currently serving life in prison without the possibility of parole. But he maintains his innocence and believes he was framed in retribution for filing a $36 million lawsuit against the county and authorities. (Avery’s nephew, Brendan Dassey, was also convicted for her murder and will be eligible for parole in 2048.)

A ‘Targeted’ Crime?

Kratz, who says he was contacted by filmmakers Laura Ricciardi and Moira Demos but declined to be interviewed for the series, believes Avery “targeted” Halbach.

He cites Halbach’s Oct. 10, 2005 visit to the property owned by Avery’s family for a photo shoot for AutoTrader magazine: According to Kratz, Avery allegedly opened his door “just wearing a towel.”

“She was creeped out [by him],” Kratz says by phone, later adding by email: “She [went to her employer and] said she would not go back because she was scared of him.”

At 8:12 a.m. on Oct. 31, the day Halbach was killed, Kratz says Avery called AutoTrader magazine and asked them to send “that same girl who was here last time.” He says that Avery knew Halbach was leery of him, so he allegedly gave his sister’s name and number to “trick” Halbach into coming.

“Phone records show three calls from Avery to Teresa’s cell phone on Oct. 31,” says Kratz. “One at 2:24 [p.m.], and one at 2:35 – both calls Avery uses the *67 feature so Teresa doesn’t know it him…both placed before she arrives.

“Then one last call at 4:35 p.m., without the *67 feature. Avery first believes he can simply say she never showed up so tries to establish the alibi call after she’s already been there, hence the 4:35 call. She will never answer of course, so he doesn’t need the *67 feature for that last call.”

Kratz Claims Further Evidence Against Avery

During his time in prison for a rape he was later cleared of, Kratz says Avery allegedly “told another inmate of his intent to build a ‘torture chamber’ so he could rape, torture and kill young women when he was released.” Kratz adds, “He even drew a diagram.”

Kratz also claims that “another inmate was told by Avery that the way to get rid of a body is to ‘burn it.’ ” Halbach’s bones were discovered in the fire pit behind Avery’s house. He says “were ‘intertwined’ with the steel belts, left over from the car tires Avery threw on the fire to burn,” says Kratz, disputing the defense’s allegation that Halbach was burned elsewhere and her bones were later moved.

“Suggesting that some human bones found elsewhere – never identified as Teresa’s – were from this murder was never established,” he adds.

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According to Kratz, Avery’s DNA, which he says was not taken from his blood, was also found under the hood of Halbach’s car, a Toyota RAV4. “How did his DNA get under the hood if Avery never touched her car? Do the cops have a vial of Avery’s sweat?” asks Kratz. Defense attorneys alleged that Avery’s blood, which was found in Halbach’s car, may have been planted, taken from a vial of Avery’s blood that was 11 years old.

Kratz also claims that a bullet, recovered from Avery’s garage, couldn’t possibly have been planted by police, as the defense also alleged. “Ballistics said the bullet found in the garage was fired by Avery’s rifle, which was in a police evidence locker since Nov. 6, 2005,” says Kratz. “If the cops planted the bullet, how did they get one fired from [Avery’s] gun? This rifle, hanging over Avery’s bed, is the source of the bullet found in the garage, with Teresa’s DNA on it. The bullet had to be fired before Nov. 5.”

Kratz, who resigned from his position as Calumet County District Attorney in 2010 following a sexting scandal, admitted that he sent suggestive messages to a crime victim and described his behavior as “deplorable” in an email. He says he had a prescription drug problem at the time. He believes, however, that “it’s exceedingly unfair to use that to characterize me as morally unfit” in Making a Murderer and says his later behavior shouldn’t have any bearing on the case.