Doug Schneider

USA TODAY NETWORK-Wisconsin

GREEN BAY - Principals in the "Making a Murderer" case will appear on Friday's "Dateline" broadcast, with a defense lawyer saying Brendan Dassey's confession was "fed to him," and an investigator insisting that Dassey's admission to murder was not coerced.

"'We didn't try to manipulate Brendan. We tried to get at the truth,' retired Division of Criminal Investigation Detective Tom Fassbender tells 'Dateline,'" NBC said in a news release Tuesday. "And I don't believe that it was a false confession. Are there parts of it that he may have not done, I don't know."

The case sent Manitowoc County resident Steven Avery and his teenage nephew Brendan Dassey to prison for the 2005 murder of photographer Teresa Halbach. The killing, and insistence by the defendants that they were railroaded by the system and should be released, formed the basis for the 10-part Netflix documentary, "Making a Murderer," released in December 2015.

Friday's hour-long broadcast, scheduled for 9 p.m., will include an interview with former prosecutor Ken Kratz, who won conviction of Avery and Dassey in separate trials.

NBC said it will also include comment from Avery’s ex-fiancée Sandy Greenman, Halbach’s friend Kim Peterson, Avery’s former defense attorney Jerome Buting, Avery’s cousin Kim Ducat, Dassey’s current lawyers, Laura Nirider and Steven Drizin; Dassey’s former lawyer Len Kachinsky and Avery’s current defense attorney, Kathleen Zellner.

Nirider, who is representing Dassey in his appeal, says the confession he gave to detectives was not voluntary. Dassey, then a learning-disabled 16-year-old, was interviewed by investigators without his attorney present.

"Those officers wanted that information in the worst way and they got it in the worst way," she said. "By feeding it straight to Brendan Dassey."

RELATED: Avery rips his former lawyers via letter

The show is slated to air three days after a hearing Tuesday in the U.S. Court of Appeals for the Seventh Circuit in Chicago, where attorneys for Dassey and the Wisconsin Department of Justice argued Dassey's conviction.

Magistrate Judge William Duffin in November ordered Dassey released from prison while his appeal is pending, but state Attorney General Brad Schimel convinced an appeals court to block the release. Duffin ruled that Dassey’s constitutional rights were violated, and that the prosecution’s investigators made false promises to Dassey during multiple interrogations of the then 16-year-old. The judge's 91-page ruling was highly critical of investigators, Dassey’s pretrial attorney and the state courts.

The trial judge prevented Kratz from introducing nine elements of evidence of "other acts" by Avery, including alleged acts of violence against his former fiancee and his niece, as well as a claim he allegedly made to another prison inmate that implied he hated women.

The news prompted buzz on social media and among online communities whose members have followed the case.

"I'm interested to see what Fassbender has to say. I think it his first time speaking out about the case," a user named "jordynpuppy" wrote on Reddit's "TickTockManitowoc" thread. "Although he will most likely will echo what others have said about Avery being convicted by a jury of his peers and how hard it is for the Halbach family to have this all being brought up again … 'cause what can they say we have all seen the confession, and the fact they bullied a kid into prison. Kratz will be the same old pulling stuff out of thin air to fit his narrative."

"Dateline," hosted by Lester Holt, airs at 9 p.m. Fridays on WGBA (Channel 26) in Green Bay and the Fox Valley. WGBA airs on Channel 13 on Time Warner-Spectrum cable in Green Bay.

Both Kratz and Buting have books due for release in the near future.

Buting's book, "Illusion of Justice: Inside Making a Murderer and America's Broken Justice System," draws from the Avery defense and from other cases. Amazon.com says the book, due for release on Feb. 28, "explains the flaws in America’s criminal justice system and lays out a provocative, persuasive blueprint for reform."

RELATED: Ken Kratz interview grows awkward

Kratz's "Avery: The Case Against Steven Avery and What 'Making a Murderer' Gets Wrong," is scheduled to be available on Feb. 21. Amazon says the book proves, "that, in this case, the criminal justice system worked just as it should."

dschneid@greenbaypressgazette.com and follow him on Twitter @PGDougSchneider