A man who fatally stabbed a teenage girl in her high school's rotunda in Abbotsford, B.C., in 2016 will not be eligible to apply for parole for 16 years, after a judge ruled the impacts of his actions have been "powerful and far-reaching."

Gabriel Klein was convicted of second-degree murder and aggravated assault in March 2020 in the attack that killed 13-year-old Letisha Reimer and seriously injured her friend.

He receives an automatic life sentence and an additional seven-year sentence for the aggravated assault, to be served concurrently.

However, Klein also received seven years' credit for time served while awaiting trial.

Klein, who has schizophrenia, applied for a hearing over criminal responsibility one week before sentencing was originally set to begin last September.

Associate Chief Justice Heather Holmes ruled in April against Klein's argument that he suffered a mental disorder that made him unable to appreciate the nature of his actions or that they were wrong.

Klein declined to speak at the sentencing hearing, but his lawyer Martin Peters said he read all of the victim impact statements.

In delivering her sentence, Holmes said Klein's moral culpability is high and not only affected his victims, and their family and friends, but also destroyed the school community's sense of security.

She says that while the trial focused on Klein, now is the time when a spotlight can be shone on Reimer, her friend and other victims of the offence.

"The victim impact statements, and there are many, make clear that she was valued as a very special person, joyful, filled with laughter, poised and confident, kind-hearted and caring, generous as a volunteer, devoted to her family, a wonderful soul with a beautiful smile, fun to be with, willing to be goofy and in an unbearable irony, full of life," Holmes said.

"The effects of losing her are many, wide and profound."