A Saskatchewan judge has ruled a teenager who pleaded guilty to second-degree murder in the 2015 death of 16-year-old Hannah Leflar will receive a youth sentence.

The judge ruled the Crown did not prove the teenager, who can not be named because of his age at the time of the crime, had enough moral blameworthiness or culpability in the crime to be sentenced as an adult.

The teen, who is now 19, received a seven-year sentence through Saskatchewan's Intensive Rehabilitative Custody Supervision (IRCS) program, with four years to be served in custody. The program is available to youths who have been convicted of a violent crime.

The victim's family was angry with the judge's decision.

"The family's upset," said Crown prosecutor Chris White. "I don't think they see this as closure."

The teen's own brother shouted: "You deserved an adult sentence," as he left the courtroom.

Had Justice Lian Schwann sentenced the teen as an adult, it would have resulted in a life prison sentence with no chance of parole for at least seven years and his identity would have become public.

In her decision, Schwann noted the teen did not physically participate in the murder, and said there was no evidence he was involved in a plan to kill Leflar prior to the day of the murder.

"She seemed to be quite swayed by the potential for success with an IRCS sentence," said White. "I'm not entirely sure the evidence bore that out."

Defence lawyer Greg Wilson believes the judge correctly followed the law.

"I get that this is not a popular sentence," said Wilson. "I get that a lot of people aren't going to like it, but Canadian law is based on consistency, is based on principles, is based on the Youth Criminal Justice Act, and at the end of the day, we felt this was going to be the appropriate outcome."

He said his client will be receiving counselling as part of his sentence and hopes to become a better person.

"He's looking forward to simply moving on with his life, and to addressing those issues that placed him in this situation." Wilson said.

Prosecutors said the justice ministry would need to review the case before deciding if there will be an appeal of the sentence.

The teen was originally charged with first-degree murder in the Regina girl's death, but pleaded guilty to second-degree murder.

Leflar was stalked and then attacked in her home by her ex-boyfriend, Skylar Prockner, on Jan. 12, 2015. The teen being sentenced was a lifelong friend of Prockner's and watched as Leflar, who he was also friends with, was stabbed at least 10 times. He did nothing to stop the slaying.

Prockner pleaded guilty in Saskatchewan Court of Queen's Bench to first-degree murder in Leflar's death and in the summer was sentenced to life in prison with no chance of parole for 10 years. Although he was a youth at the time of the murder, he was sentenced as an adult.

The teen who watched his crime cannot stay in a youth facility after he turns 20. He will serve part of his sentence in provincial jail before being moved to a federal penitentiary. A placement hearing will be held to determine where the teen will begin his sentence.

Lied for 2 years

For more than two years, the teen maintained he didn't know what was going to happen when Prockner messaged him to bring a knife to school and meet him after classes were over that day.

He told the court while in the witness box that he didn't know the plan was to kill Leflar when Prockner said they were headed to her house, or when they were parked outside waiting for her to return home from school.

After a day of answering questions from his own lawyer, Crown prosecutor Chris White was able to cross-examine the teen.

On Sept. 26, the teen admitted in court that he had been lying.

After about three hours of questioning, he said that at the time of the murder he wished death upon Leflar.

The revelation caught those in the courtroom by surprise, including Schwann, who called them "surprising and blunt statements."

"I wanted to help Skylar with her murder," the teen said.

Hannah Leflar a few months before she was murdered in her own home. (Submitted by Jeff Leflar and Lore Orasan)

The teen went to school the day after the murder and was consoling students about Leflar's killing.

That same day, he texted his brother to brag about Leflar being dead.

The teen admitted he misled the psychologist who wrote a report on him and faked a recent self-harm attempt so he would be transferred to another unit in the youth facility where he has been since he was arrested.

White said the teen's testimony "changed the landscape" of the sentencing. He called it an "unravelling."

"He committed perjury for upwards of four hours. He lied through his teeth. He lied to everyone," White told the judge.

"He just wanted to kill, he looked forward to it," said White, adding the teen had no motive.

Hannah's parents said she loved animals. She is shown here with the family cat, Loki. (Submitted by Janet Leflar)

I wanted to help Skylar with her murder. - 19-year-old who cannot be named

The teen's lawyer, Greg Wilson, argued his client's surprising revelations in court showed maturity. He said it showed remorse and empathy that he didn't want to hide his thoughts from Leflar's family any more. He said the offence committed by the teen doesn't meet the bar for an adult sentence.

The teen told court he was sick of telling lies.

When asked if he looked forward to murdering his friend, he told the court, "I was, yes."

Impact of murders

During the two-week sentencing hearing in September, Leflar's family and friends shared how her murder has impacted them.

A total of 13 statements were read aloud in court, each illustrating the pain caused by the killing.

Leflar's stepmother, Lore Orasan, called the teen "more dangerous" than Prockner, and referred to the pair as "the two monsters."

"He infected us with a chronic, debilitating disease that had no cure. The pain is excruciating," Orasan said.

Skylar Prockner received an adult sentence of life imprisonment with no chance of parole for 10 years for the murder of Hannah Leflar. (CBC)

Leflar's mother, Janet Leflar, called her daughter "everything I hoped she'd be." She told the court she spends her days wracked with guilt.

She spoke about how the teen was welcomed into their family home and often had meals with them.

"Monsters are real and they look like people," she said. "The most dangerous monster is the one that comes disguised as a friend."