'Making a Murderer' defense attorney says blood vial evidence could still prove Steven Avery was framed

Since Netflix's "Making a Murderer" aired in December, a lot of information that wasn't included in the series has come to light.

On Saturday, Investigation Discovery special "Steven Avery: Guilty or Innocent" went over the case once again with new interviews with the attorneys, experts, and reporters who covered the trial of Avery, who is currently serving a life sentence for the 2005 murder of photographer Teresa Halbach.

Avery's defense centered on the theory that the Manitowoc County, Wisconsin man was being framed for the murder by local police. Previously, Avery had been exonerated for the assault of a female jogger after already serving 18 years of his sentence. At the time of the investigation into Halbach's murder, he had an ongoing $36 million civil suit against the county that also included the policemen involved in his conviction.

"What I feel like, they're going to railroad me again," Avery told a reporter during the investigation. "They set me up the first time. I had to do 18 years to prove my innocence. Now, they want to redo it and see if they can get me, plant evidence so I don't get back out."

One of the defense's biggest findings to support its theory was a vial of Steven Avery's blood from the previous crime's investigation. To the defense team, it showed evidence of tampering - a small hole was found in the lid - and could have been used to plant Avery's blood in Halbach's car.

But since the documentary aired, we've found out that the prosecutors had a witness, a nurse who would say that she made that hole in the lid and that it was the typical way to fill a test tube. That would seem to take away any proof of framing the evidence provided.

But on Saturday's ID special, Avery's defense attorney Jerry Buting explained why the blood vial had other evidence of tampering.

"This evidence tape had been cut, by who? When?" Buting said of the tape on the box that held the vial.

He also pointed out, "If you look carefully, there's blood in between the stopper and the glass, which you can only get if the stopper was taken out. That looked suspicious."

Dassey is currently appealing his conviction. On Friday, NBC's Dateline aired its own special about the case. On it, Avery's new attorney, Kathleen Zellner, said that new forensic testing could lead to another exoneration for her client.