Travis Vader believes there is one sure thing in his life: He will be found not guilty of murder.

"There's never been a time through the last six years that I didn't know what the outcome was going to be," Vader said in an exclusive telephone interview with CBC News. "And that's found not guilty and carry on with my life."

After a pause, he added, "It's just, why did they make it take six damn years?"

As the trial of the murder of Lyle and Marie McCann comes to a close, Travis Vader tells Janice Johnston how he feels about his treatment by the police. 1:29

Vader approached CBC more than a week ago through friends, requesting an interview. Late last week, he called from the Edmonton Remand Centre. The interview, which lasted 40 minutes, was likely recorded by jail officials.

It marked the first time Vader has spoken publicly, and at length, about his first-degree murder trial, or about the RCMP investigation into the July 2010 deaths of Lyle and Marie McCann. The elderly St. Albert, Alta., couple were last seen alive on July 3, 2010. Their burned motorhome was found two days later near Edson, Alta. The SUV the couple towed behind the motorhome was discovered July 16, 2010. Their bodies have never been found.

The trial at the Court of Queen's Bench in Edmonton began in March. After more than 50 days of testimony, all the evidence is now in. Closing arguments will be delivered by the Crown and defence later this month.

In the interview, Vader sharply criticized police and prosecutors. He called the RCMP investigation a "witch hunt," and described the case as "a fiasco."

"The Crown put together a very, very shoddy incomplete case," he said. "You have to prove [beyond a reasonable doubt]. And they did not."

A spokesman for Alberta Justice declined comment on behalf of the Crown.

In 2014, Vader launched a $1-million wrongful-prosecution lawsuit against more than four dozen RCMP officers, Crown prosecutors and jail guards. No statements of defence have ever been filed.

"I plan to expose the RCMP for what they are. And I plan to expose the Crown and the justice system for what it is," he said.

Alleges police brutality in latest arrest

Vader's trial began in early March. He has been back behind bars since May 10, when RCMP arrested him for allegedly breaching his bail conditions. He was subsequently charged by Edmonton police with possession of a stolen truck and breaking and entering.

He claims the Mounties used unnecessary and excessive force to arrest him in west Edmonton.

"I put my hands up to be arrested and they attacked me," he said. "They threw me on the ground. Stomped the shit out of me. You know, what did I do to warrant that? Nothing. Did they have to chase me down like a dog? Treat me like an animal? No."

RCMP Insp. Gibson Glavin declined to comment on any of Vader's allegations.

But Vader claims he was unable to move his arm for two weeks after the arrest. He called his latest run-in with police "minor compared to what I'm used to."

'Witch hunt'

"It is personal," Vader said. "You can see it in their face, in their gestures, how they deal with you. They're just so happy to just get their hands on you, to be able to hurt you or do something. Because I think they're so frustrated this case isn't going the way they wanted. This witch hunt that they've created."

The accused killer alleges the RCMP told lies to his friends and family to advance their theories, laid "trumped up" charges just to keep him in jail, and may have convinced others to commit illegal acts. He points to a modified Mr. Big sting Mounties ran on his sister, Bobbi Jo Vader, in November 2011.

Vader said he believes undercover officers took advantage of her during the sting.

"She was already on conditions not to be involved with alcohol. Not to be involved with drugs. They took her to the bars and got her drunk. And it would trigger her addiction. And she'd say anything or do anything."

During the trial, Bobbi Jo Vader testified during cross-examination by the defence that she used the "thousands of dollars" she received from undercover officers to feed her crack addiction. The Crown called no evidence that came from the Mr. Big sting.

Not in McCann SUV 'under my knowledge'

The Crown admits it has a circumstantial case against Vader. But it did enter key pieces of forensic evidence during the trial.

The prosecution has said Vader's blood was found on the front console of the McCann's Hyundai SUV. An RCMP expert testified there was a one-in-three-trillion chance of it being anyone else's blood. His DNA was also found on a beer can in the SUV and on the steering wheel.

Defence experts disputed the DNA and fingerprint evidence. Vader insists he should not be linked to the vehicle.

"I was not in the SUV," he said.

"At least, I was not in the SUV under my knowledge. I sure as hell wasn't driving around having a good old time as they say."

Denies drug use

The Crown has painted Vader as a desperate methamphetamine addict who attacked the elderly St. Albert couple to get money to feed his habit.

Vader vehemently denies he has ever used the drug. That's in direct contrast to testimony heard from a number of Crown witnesses during the murder trial.

For example, Willie Nikolyuk testified: "We started doing drugs together. Smoking speed. That's how I got to know him."

Vader's ex-girlfriend Amber Williams told the court she and Vader took drugs together.

"We both used it quite a bit," she said. "We were both constantly doing it. And that's mainly the reason why we split up."

Vader is accused of testing positive for methamphetamine in May after providing a court-ordered urine sample to RCMP. He claims he was taking an over-the-counter cold medication at the time that contained amphetamine.

Future includes apologizing to children

Vader told CBC he is making plans for the future, convinced he will be acquitted when Justice Denny Thomas hands down his decision at the end of August or in early September.

The first thing he plans to do is "apologize to my children for being gone, for being away so long," he said.

"You be a man," he said. "You buck up. You go back to work.

"I can go back to being the person that I was. I was a father that worked his ass off his entire life for 20 years in the oilfield."

Vader is engaged to a woman he describes as "a wonderful person." But he has not made any wedding plans yet.

'I know I'm going to be in trouble'

He saves his few kind words for his fiancée and his lawyer Brian Beresh.

Vader calls Beresh "a superb lawyer" who "goes that extra 10 miles."

Toward the end of the interview, a recorded message warned the call would end in one minute.

Vader was asked if there was anything else he wanted to add. He delivered a message to Beresh, who was not aware of his interview with CBC.

"Sorry, Brian, but I thought this needed to be done," he said, adding with a nervous chuckle, "I know I'm going to be in trouble."

janice.johnston@cbc.ca

@cbcjanjohnston