WISN 12 investigative reporter Colleen Henry wrote to Steven Avery, the subject of the Netflix documentary series Making a Murderer, asking if he'd be willing to be interviewed about the series.

On Thursday, she received a three-page, handwritten letter from Avery, who is serving a life sentence for the 2005 murder of Theresa Halbach, in which he maintains his innocence and accuses his former girlfriend Jodi Stachowski of accepting payment to change her story.

In a typed note accompanying the letter, Avery wrote, "The real killer is still out there. Who is he stalking now? I am really innocent of this case and that is the truth!!! The truth will set me free!!!!!!!"

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His letter addresses Stachowski's changing of her story. In the documentary, Stachowski defends Avery, but she recently told Nancy Grace that he's a "monster" and she now thinks he killed Halbach.

Avery suspects that Stachowski was paid off, writing, "How much money Jodi get to talk bad!"

Avery writes that he's willing to do an interview with WISN, but the Department of Corrections has said it will not allow it.