MEADOW LAKE, Sask. -- A teenager who killed four people and injured seven others during shootings at a home and a high school in northern Saskatchewan apologized Friday to those who died, those who survived and their families.

People wept as the teen addressed each of his victims at a hearing to determine if he is sentenced as an adult or a youth for his actions in La Loche in January 2016.

The teen tearfully said if he could talk to teacher Adam Wood, who died from his injuries, he would tell him he was sorry.

"If he was here right now, I would say to him: 'I didn't really know you, but I heard you were a good person, a kind person ... and I'm sorry I shot you. You were not a target."'

The teen said the same about teacher's aide Marie Janvier, who also died, and apologized to her mother.

"I'm sorry I ruined your life and took your daughter away. All she wanted to do was help students," he said to Jackie Janvier, who sat through every day of the two-week sentencing hearing.

Some of the seven survivors are students who can't be named.

About substitute teacher Charlene Klyne, the teen said he was sorry for shooting her while she was sitting in her classroom.

"I'm sorry for ruining your life that day," he said. "You weren't someone who was a target."

Klyne lost all vision in her left eye, can only see dark shadows in her right eye and has numerous pellets lodged in 13 different spots from her jaw to her chest. She's been told it's too risky to have surgery to remove the pellets.

She was not in court.

The teen said he didn't know what he was thinking when he pulled the trigger.

Earlier Friday, a neuropsychologist testified for the defence that the teen had an IQ of 68, which is considered well below average. Dr. Monty Nelson said "thinking quickly was a major difficulty" for the teen.

A defence psychiatrist testified that the teen has symptoms of post-traumatic stress disorder, an intellectual disability, major depressive disorder and displays signs of fetal alcohol syndrome.

A child psychiatrist who testified for the Crown said the teen did not come across as being clearly developmentally delayed or slow.

The teen -- who cannot be named because he was just shy of his 18th birthday when the shooting occurred -- killed brothers Dayne and Drayden Fontaine in a home before shooting up the high school where Wood and Janvier died.

During the first week of the sentencing hearing in May, an agreed statement of facts detailed the shooter's murderous path from the home to the community's high school.

Court heard Dayne, 17, pleaded for his life before he was shot 11 times, including twice in the head. Drayden, 13, was shot twice.

Surveillance footage captured his frightening walk through the halls, his shotgun raised, as students and staff ran in fear.

When police arrived, the shooter ran into a women's washroom where he put his weapon down and gave himself up.

He pleaded guilty last fall to two counts of first-degree murder, two counts of second-degree murder and seven counts of attempted murder.

The teen told court he knows the boys' mother forgives him.

"I know she knows I am sorry for what I did."

Court heard from Alicia Fontaine last month. She said the teen called her two days after the shooting to apologize and she forgave him.

Lawyers are to make final submissions to Judge Janet McIvor on Aug. 25.

McIvor said she would release her decision and sentence the shooter in La Loche, but no date was set.

La Loche Mayor Robert St. Pierre suggested McIvor should consult the community first.

"There's some mixed emotions," the mayor said outside court.

"A lot of people have expressed they'd like to have it in La Loche for some closure, and some have expressed they would rather not have it in La Loche because it will dredge up bad memories and bad emotions."