Jerry Buting, former defense attorney for Steven Avery, whose story is told in the hit Netflix series Making A Murderer, says he believes police planted evidence against his client to obtain a conviction. He says he believes a car, car keys, electronics, and bones were tampered with by police.

“He’s suing them for $36 million for his wrongful conviction. And it’s not just the money. He’s embarrassing them. So they had a lot against Steven Avery. A lot of motive,” Buting tells Dr. Phil on Monday’s episode.

TELL DR. PHIL YOUR STORY: Conflict so big it needs a Dr. Phil solution?

In 2005, Avery was arrested as s suspect in the murder of 25-year-old Wisconsin photographer Teresa Halbach. At the time, Avery was suing Manitowoc County, WI for wrongful imprisonment after serving 18 years in prison for a rape he was eventually exonerated of because of DNA evidence. Many believe law enforcement framed him in retaliation for his lawsuit.

WATCH: Investigator Featured In ‘Making A Murderer’ Adamant There Was No Planted Evidence Or Coercion

In the video above, Buting, author of the new book, Illusion of Justice: Inside “Making A Murderer” and America’s Broken System, explains how Halbach’s car key became a key piece of evidence in the case and why he believes it was planted in Avery’s bedroom.

“The first search, they were in there for two-and-a-half hours in that little trailer. This is a small place. They seized other items from his bedroom and yet, they don’t find this key,” says Buting, adding that the key wasn’t found until the sixth or seventh search of Avery’s bedroom. Buting also says that the key appears to be a spare key, as it doesn’t have the markings of a key that is used daily. “It had none of her DNA on it in all of those crevices where she was supposedly handling it for two years that she had the car. Only his DNA is found on it, and it’s a very small amount,” he says. “On the one hand, they want to make Steven Avery into this criminal mastermind who’s able to clean up this huge mess in his house, finding no DNA or blood anywhere. And yet, he’s stupid enough to put the key in his bedroom?”

WATCH: 6 Reasons Former Prosecutor Says He Believes 'Making A Murderer' Subject Steven Avery Is Guilty

Avery and his nephew Brendan Dassey were convicted of Halbach’s murder. Avery is currently serving a life sentence without the possibility of parole. In August 2016, a federal magistrate overturned Dassey’s murder conviction finding that the teen's confession was unconstitutionally coerced by investigator Tom Fassbender and his partner. Yet, he is still in prison today as that ruling is being appealed.

On Monday’s episode, Buting faces off with Ken Kratz, the prosecutor who put Avery behind bars and co-lead investigator Tom Fassbender who was accused of coercing a confession out of Dasssey. Check here to see where you can watch.

TELL DR. PHIL YOUR STORY: Have a headline-making story in a small town?

Why Attorney Featured In ‘Making A Murderer’ Blames Prosecutor For Steven Avery Not Getting A Fair Trial