WINNIPEG -- The Crown argued Tuesday that a man charged with killing a Manitoba teenager convicted himself with his own admissions on secret police recordings, but the defence said numerous forensic holes in the prosecution's case have left reasonable doubt.

It will soon be up to a jury to decide whether Raymond Cormier, 56, murdered Tina Fontaine, a sexually exploited 15-year-old whose body was wrapped in a blanket and dumped in Winnipeg's Red River.

Tina's death in August 2014 prompted renewed calls for an inquiry into missing and murdered Indigenous women and the ensuing investigation and trial have been watched closely by people from coast to coast.

There's no DNA evidence linking Cormier to Tina and doctors called to testify said they could not definitively say how she died.

Prosecutor Jim Ross said Cormier's own words, captured during an elaborate, six-month undercover police sting are enough for a conviction.

"This case can be quickly decided because the words he speaks are admissions of murder," Ross told the jury in his final submission. "Plain and simple."

Over three-weeks of testimony, the jury heard how Tina's relatively stable upbringing on Manitoba's Sagkeeng First Nation spiralled out of control when her father was murdered and she descended into life on Winnipeg's streets.

She and her boyfriend met the much-older Cormier in the summer of 2014. The jury heard Cormier gave the couple a place to stay, gave Tina drugs and had sex with her.

The toxic relationship was volatile.

Witnesses remember Tina and Cormier fighting in the street over a stolen truck and Tina accusing him of selling her bike for drugs. Tina went so far as to report a stolen truck to police.

She was in the care of social services and was staying at a Winnipeg hotel when she was reported missing Aug. 9.

Her body was found Aug. 17, wrapped in a Costco duvet cover that several witnesses said was similar to one Cormier owned.

Experts testified the river had washed away any DNA on the cover, but with Cormier on their radar, investigators went undercover and offered him an apartment.

Bugs captured what formed the heart of the Crown's case.

Cormier was recorded telling a woman that he would make a bet that Tina was killed because he had had sex with her and then "I found out she was 15 years old."

In another recording, Cormier was heard arguing with a woman and saying that there was a little girl in a "grave someplace screaming at the top of her lungs for me to finish the job. And guess what? I finished the job."

"He's exposed here legally ... it could make him a pedophile," Ross argued. "You all know who the little girl in the grave is."

Defence lawyer Tony Kavanagh took issue with the quality of the recordings.

He asked the jury to consider Cormier's denials when interviewed by police.

"We say Mr. Cormier was telling the truth when he said he didn't kill Tina Fontaine," said Kavanagh. "We say you should find Mr. Cormier's version and denials believable. We say that raises doubt and you must acquit."

With no DNA evidence and no cause of death, Kavanagh said the Crown can't prove that Tina didn't die from a drug overdose or naturally in what he called the "underbelly of the city."

He said that alone is enough to create reasonable doubt, and Cormier shouldn't be convicted just because of his rough lifestyle.

"You can't convict Mr. Cormier because he's a drug addict, a thief or politically incorrect. He's not a saint but you've got to look at the evidence," Kavanagh said.

Justice for Tina, Kavanagh argued, should not come at the expense of injustice for Cormier.

"It's undisputed that Ms. Fontaine had a tragic life. That's not the problem we're solving today. This trial is about one thing -- is Mr. Cormier guilty beyond a reasonable doubt of killing Ms. Fontaine?"

The defence lawyer urged the jury to be careful when reviewing the evidence.

"It is a largely circumstantial case," he said. "You don't convict on a mystery or a whodunit. It's not an Agatha Christie novel you're trying to determine here."

Justice Glenn Joyal is to give jurors their instructions Wednesday.