Trent Butt, a Newfoundland man who killed his only child in what the Crown called an act of vengeance against his estranged wife, was found guilty of first-degree murder Friday in Quinn Butt's death.

The Supreme Court jury delivered its decision on Friday afternoon in a case that has captivated Newfoundland and Labrador for almost three years — the story of a father accused of killing his five-year-old daughter and then setting his home on fire.

The St. John's courtroom, so crowded with onlookers that some had to stand, erupted with emotions, including tears and gasps, when the jury's verdict was announced.

Quinn's mom, Andrea Gosse, wept as she hugged friends and family in the courtroom following the verdict.

She and other supporters wore purple, one of Quinn's favourite colours.

<a href="https://twitter.com/hashtag/ButtTrial?src=hash&ref_src=twsrc%5Etfw">#ButtTrial</a> Andrea Gosse tears of relief. First degree murder conviction for Trent Butt <a href="https://t.co/ZLFHgDFEqa">pic.twitter.com/ZLFHgDFEqa</a> —@CBCMarkQuinn

The two-week trial was emotional, with jurors listening to heart-wrenching testimony from Gosse, as well as the first responders who found the girl's dead body in Trent Butt's burning Carbonear home in April 2016.

An autopsy could not determine the exact cause of death for Quinn Butt, although Dr. Simon Avis testified that Quinn could have been smothered.

The jury was told that Butt intended to end his life, and that he had slashed his wrist and neck and doused Quinn's bed with gasoline.

"His only failure in this murder-suicide plot was that he survived," said prosecutor Lloyd Strickland.

The jury was also presented with a letter that an evidently suicidal Trent Butt had left at the scene before he lit his house on fire. In the lengthy letter, Butt blamed Gosse for ruining his life.

'It's for Quinn'

Supporters flanked Gosse, who was overcome with emotion, as she spoke Friday on the steps of the courthouse in downtown St. John's after the verdict.

"I feel like since I left Trent I've been fighting with the system for three years. And this is the first time anything has gone Quinn and [my] way," Gosse said, as she cried.

"If anything else other than [first-degree murder] would have come out, it just would have been a punch in the stomach. It's for Quinn."

Andrea Gosse, right, who is Quinn Butt's mother, is flanked by supporters as she stands on the steps of the courthouse in St. John's after the verdict against her estranged husband. (Bruce Tilley/CBC)

Gosse said she doesn't know if the verdict brings total closure, but there is relief that the trial is over.

Earlier in the day, jurors came back with a question and reviewed some evidence as part of their deliberations.

Friday marked the second day of deliberations for the 12 jurors, who had been sequestered the previous afternoon.

The Crown and defence wrapped up closing arguments Thursday morning.

Emotions ran high

In his instructions to the jury, Justice Donald Burrage reminded them they must use reason to reach a decision, not emotion.

Trent Butt has been found guilty of first-degree murder in the killing of his daughter, Quinn. (Mark Quinn/CBC)

Butt was originally charged with both first-degree murder and arson, pleading not guilty to both. At the onset of the trial, though, he changed the arson plea to guilty, acknowledging he started the fire at his home.

A sentencing hearing is scheduled for April 23 to deal with the arson plea. The family will also be given the chance to provide victim impact statements.

A first-degree murder conviction carries an automatic life sentence of 25 years without parole.

"We're satisfied it's the proper verdict," prosecutor Strickland said on the courtroom steps minutes after the jury convicted Butt.

Crown prosecutor Lloyd Strickland said he believes Butt taking the stand showed the jury he had 'no response' to the Crown's case against him. (CBC)

"We expected there would be a finding of first-degree murder, and that's why he was charged with first-degree murder."

When asked what he believes was the turning point for the jury during the trial, Strickland said Butt taking the stand to give testimony made it "clear Mr. Butt had no response to the Crown's case."

RCMP Supt. Holly Turton responded to the conviction, saying the force was pleased with the verdict given the "strong and thorough" case that investigators prepared, "even though the verdict provides little solace for those who loved Quinn and continue to grieve."

Supt. Holly Turton and lead investigator Cpl. Peter Gosse responded to the case after Friday's verdict. (Meghan McCabe/CBC)

Cpl. Peter Gosse, who led the investigation, said the team was confident in the evidence they provided.

"There's hundreds of hours that go into these types of investigations," he said, noting that at times 30 to 40 members were working on the case.

Gosse commended the volunteer firefighters and paramedics who responded to the murder scene and encouraged first responders to seek support if needed.

"We are all parents, most of us," he said. "These types of investigations are sensitive, and it takes a toll on people."

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