The 12 jurors who are now deliberating the fate of Luka Magnotta spent 10 weeks hearing testimony at his first-degree murder trial in Montreal, but they did not hear all the evidence gathered by investigators.

In the jury’s absence, Magnotta’s taped audition for a plastic surgery reality show was played in Superior Court. A photo was also presented that seemed to promote the video the accused killer of university student Jun Lin uploaded online showing parts of the crime.

Luka Magnotta and Jun Lin are seen on a still from a surveillance video captured inside Magnotta's Montreal apartment building on May 24, 2012. (Montreal police )

Jury members were also unaware that Magnotta's demeanour changed when they were in the courtroom.

As testimony was presented, the 32-year-old spent much of the time hunched over, with his forehead nearly touching his knees. But as legal points were being debated without the jury present, Magnotta was often sitting up straight, alert and attentive.

The contrast in behaviour was so evident that Crown prosecutor Louis Bouthillier pointed it out to the judge towards the end of the trial, saying Magnotta was "laying low" when the jury was in, but when jurors were out of the room, "his behaviour is very different."

Bouthillier wanted to ask the Crown's psychiatric expert about it in front of the jury, but Justice Guy Cournoyer indicated it was too late to introduce new material not included in the expert’s report.

Magnotta admitted to killing and dismembering Lin, 33, in his Montreal apartment in May 2012, but his defence team argued he should not be held criminally responsible because he suffers from schizophrenia, which pushed him into a psychotic state at the time of the crimes.

The Crown alleges Magnotta planned the killing months in advance.

Photo promoting grisly video

In the jury’s absence, the court saw a photo that may have been distributed online weeks before the crime was committed, allegedly to promote the video posted online and played in court which shows some elements of the killing.

The photo shows Magnotta wearing a purple hooded sweatshirt with a screwdriver in his hand, standing in front of a Casablanca movie poster that is featured in the graphic video.

A photo of Luka Magnotta in front of a Casablanca poster holding a screwdriver was not entered as evidence. This image, taken by police after investigators recovered the poster from the trash outside Magnotta's apartment building, was seen by the jury. (Montreal police)

The jury was not allowed to see the photo because the Crown decided not to include it in its original evidence.

"We pondered on that a long time, but we chose not to because we could not prove what we wanted to prove," Bouthillier said, adding it was impossible for investigators to determine exactly when the photo was posted online.

Defence lawyer Luc Leclair objected to the jury seeing the photo, calling it, "extremely incriminating."

"It proves first-degree murder," he told the judge.

The Crown was allowed to ask questions about the photo without showing it, because the image was alluded to in a report written by one of the psychiatrists hired by the defence.

'Powerful' reality show audition excluded

The jury also did not see a filmed audition Magnotta produced in early 2008 in an attempt to be cast on a plastic surgery reality show.

The Crown argued it was important to watch because during the audition Magnotta does not appear to show disorganized thought or behaviour. It was filmed at the same time he was complaining to psychiatrists about hallucinations and other symptoms of schizophrenia.

In the video, a relaxed Magnotta details the plastic surgery he wants to have done, and talks about his obsession with his appearance.

The producer asked him: "How important are your looks to you?"

"Number 1 is looks, number 2 would have to be intelligence, and I don’t know what the rest are, all I care about is number 1," Magnotta says with a laugh.

He even mimes looking at his reflection in a spoon at restaurants, while talking about how people keep telling him he is vain.

The judge called the video a "game-changer" because of its "eerie, timeless quality."

He ultimately ruled that it was not admissible because it was recorded four years before Lin's slaying and could potentially distract the jury from the main point of its deliberations: Magnotta's state of mind at the time of the killing.

Before the trial even began, a Quebec judge prevented investigators from getting their hands on an academic interview that researchers from the University of Ottawa conducted with Magnotta in 2007.

The accused participated in a study surveying sex workers under the condition that his interview remain confidential, a promise the court upheld in denying the police access.

Antagonistic tone

Exchanges between Cournoyer and the lawyers were not always amicable during the 10 weeks of testimony. The judge often expressed concern over time being wasted.

While the defence was arguing its case, detailing the symptoms of mental illness that Magnotta complained about earlier in life, the judge asked how much longer Leclair was planning to dwell on the accused's teenage years.

Cournoyer also chastised the defence lawyer for focusing on minute details.

"You are arguing about crumbs in the periphery of the case, probably to establish a grounds for an appeal," the exasperated judge once told Leclair.

The judge didn’t spare Bouthillier either.

"We're losing precious time with sideshows, side issues – things that would not have arisen if proper procedure had been followed," Cournoyer once told the Crown prosecutor.

More details heard in jury’s absence:

A correctional officer at the Rivières-des-Prairies detention centre where Magnotta is detained alleged that the accused was not taking his medication and threw pills into the toilet in September 2014. The judge did not allow the Crown to ask Magnotta's treating psychiatrist, a witness for the defence, about the allegation because he ruled the probative value was "minuscule."

Magnotta, right, is seen with an unidentified man in a photo from a memory card recovered by police and presented as evidence in court. Prior to the photo being taken, a video was shot of the man gagged and bound to a bed. It was not shown to the jury. (Montreal police)