MEADOW LAKE, Sask. -- A teen who fatally shot four people at a home and in a school in northern Saskatchewan told police he had regrets about the shooting.

Dayne and Drayden Fontaine were killed at their house in La Loche in January 2016 before the shooter went to the high school, where he killed a teacher and a teacher's aide, and wounded seven others.

The teen was asked in a videotaped police interview, which was played at his sentencing hearing Thursday, how he felt when he thought about killing the two brothers.

"I didn't plan to shoot them, man ... They weren't part of the plan," he said, crying, in the video.

The officer asked him what the plan was.

"Go to the school and shoot the f---ing kids," said the teen.

The teen was also asked what he would say to Dayne and Drayden now.

"Tell them that I'm sorry, man."

The video was recorded Oct. 29, 2016 -- the day after the teen pleaded guilty to two counts of first-degree murder, two counts of second-degree murder and seven counts of attempted murder.

Defence lawyer Aaron Fox said outside court Thursday that the video shows his client's behaviour.

"I think some of it's obvious that he has some issues, with some cognitive issues and some social issues, and some developmental issues, and I think that's consistent with some of the evidence we see elsewhere as well," said Fox.

The sentencing hearing is to determine if the teen, who was just shy of his 18th birthday at the time of the shootings, should be sentenced as a youth or an adult. He can’t be named because he was 17.

The Crown will call more witnesses Friday and then the hearing will be adjourned until June 13. Fox said the Crown is expected to have one more day of evidence when the hearing resumes in June, and then the defence will present its case.

Some victims have already told the court that the teen should be sentenced as an adult because of the severity of the crime.

Court has heard that shooting happened when the teen and the brothers were on lunch break from school. They went to the brothers' home, where the teen got a rifle out of a bedroom.

He shot Dayne Fontaine 11 times -- twice in the head -- and Drayden twice, including in the back of the head.

The boys' mother, Alicia Fontaine, told court in Meadow Lake, Sask., that the teen called her two days after the shooting to apologize.

"I may be angry, but I'm not angry at him," Fontaine said.

"I talked to him. He was crying. I forgave him. You can forgive, but you'll never forget."

If it were up to her, Fontaine said, she would not press charges in the deaths of her sons.

"It is true, my whole world is gone, but I know my babies are in a place where there is no pain," she said. "I have forgiven you."

The shooter's mother said the family has also forgiven her son for "this horrible crime."

"I was in shock like everyone else," she told court. "I never knew this was going to happen."

The teen's mother said she feels guilty, although she knows the shooting wasn't her fault.

"I am not a bad mother or person. If I knew and seen the signs that he was struggling in life, I could have stopped all of this from happening," she said.

"Sometimes, as parents, we are unaware of the struggles that our children have."

Video surveillance from the school shows the teen walking and running through hallways firing a shotgun. Teacher Adam Wood and teacher's aide Marie Janvier were killed and seven others were hurt.

In the police interview, the teen is asked who he was targeting when he went into the school.

"Nobody," he replied.

The officer asked the teen who he was looking for when he was trying to open doors.

"Teachers and students," he said.

The defence has said there is no simple reason behind the shooting and little about the motive has been made clear so far.

Earlier in the interview, the shooter said he never felt bullied. The officer also asked the teen if he felt the school had "wronged" him.

"Not really," he said. "I don't think so, no."

A youth convicted of first-degree murder and not sentenced as an adult receives a maximum 10-year sentence under Canadian law, with no more than six of those years spent in custody. The sentence becomes life in prison with no chance of parole for 10 years if the youth is sentenced as an adult and is between 16 and 18 years old.

--- with files from CTV Saskatoon

Angelina Irinici is in Meadow Lake for the sentencing hearing. Follow her coverage: