Steven Avery's lawyer blasts 'bloodsucking' prosecutor over book deal

"Making a Murderer" prosecutor Ken Kratz just announced that he's writing a book, and already Steven Avery's attorney has a review.

Kathleen Zellner, who earlier this month said she is now representing Avery, took to Twitter on Sunday to take aim at Kratz — who prosecuted Avery in the Teresa Halbach murder trial — over the book deal.

In the tweet, Zellner included a letter that Kratz wrote to Avery.

Also Read: 'Making a Murderer' DA Ken Kratz Is Writing a Tell-All Book 'Proving Steven Avery's Guilt'

"Kratz letter to SA:Confess so I can write book & profit," Zellner tweeted. "This bloodsucking gives vampires a bad name."

In the letter, Kratz laments that Avery — who has maintained his innocence in the murder — wouldn't tell Kratz his "whole truthful story." Kratz also alludes to writing a book about the Avery case in the letter.

"By the way, the difference between you and famous convicted murderers from the past is they told their whole truthful story to someone, who then wrote a book about what actually happened and people got to understand both sides," Kratz wrote in the letter. "I was willing to do that for you … but if you are going to continue to lie about what happened between you and Ms. Halbach, I am not interested."

Also Read: Steven Avery Faces 'Uphill Slog' to Prove Innocence, Legal Experts Say

On Monday, Kratz told TheWrap that he hopes the book will prove Avery's guilt, which has been called into question by the public after the December premiere of the Netflix documentary series "Making a Murderer."

"I believe somebody needs to stand up for the cops, the courts, and the victim by telling the truth and setting forth the vast amount of evidence proving Avery's guilt beyond a shadow of a doubt," Kratz said.