The new arrests are of two 16-year-olds, a male and a female, and both are in custody for first-degree murder. They have not yet been charged. Those arrests bring the total number to four, after an 18-year-old and a 14-year-old were arrested and charged with first-degree murder on Monday.
Video: Four teens arrested in 14-year-old Hamilton boys killing
He was attacked behind his high school just before 1:30 p.m. ET on Monday while he was with his mother. His death marks the city's ninth homicide in 2019.
"This entire incident is disturbing. It's difficult to comprehend right now, to be honest with you. I can't imagine the way the [victim's] family feels right now," said Det.-Sgt. Steve Bereziuk during a media update Tuesday afternoon.
At this point, I can tell you that we are satisfied based on evidence that there is some element of pre-planning… and premeditation to this homicide, Det.- Sgt. Steve Bereziuk said while updating reporters about the case on Tuesday afternoon.
Teen slain in front of mom outside Hamilton school was targeted
He added police have received help from numerous witnesses, and had located a knife near the scene that's believed to be the weapon used in the attack.
We will continue to work with our police partners on trying to understand what happened in this incident because it is a tragic loss of life. I can only imagine what the mother is experiencing at this point in time, Figueiredo said.
"I think this is one of these investigations that hits the heart of the community. It's very serious and people sympathize."
People are feeling a range of emotions and we want to be present not only for the staff but we also want to be present for our students so they can express how they are feeling, he told reporters on Tuesday morning.
Ontario teens stabbed a 14-year-old to death outside of school, in front of his mother
The first two accused made brief appearances at the John Sopinka Courthouse on Tuesday. Their names are covered by a publication ban. They remain in custody ahead of their next scheduled court appearance on Oct. 21.
Both are barred from contacting a list of 26 people whose names were read out in court. Bereziuk said many of those names are people who came forward to help with the investigation and he expected that list to grow.
When the 14-year-old left court in a white court outfit, he did not look at or talk to anyone other than his lawyer.
As the 18-year-old left after five minutes in court, he waved to people in the front row who waved back. He spoke only with his lawyer.
Berezuik said the teens were charged with first-degree murder because investigators are "satisfied based on evidence that there is some element of pre-planning."
Our hearts are broken by the news that a 14-year-old student has died, Manny Figueiredo, the boards director of education, said in the statement. There are no words that can begin to describe how shocked we are to learn about this loss.
Wary students headed back to class Tuesday morning with police tape still up and the school's Canadian flag at half-mast.
2 teens face first-degree murder charges in death of Hamilton student
They arrived as if it were an ordinary morning — and yet it wasn't. Kids gravitated together at the front of the school, most at a loss for what to do or say faced with their schoolmate's death.
Students said they were stunned by the idea that there would be "an empty desk" where their classmate normally sat. Karissa Flanagan, who had been in classes with the victim, said that the police presence outside the school served as a constant reminder that he was truly gone.
"You don't expect something [bad] to ever happen, especially at 14," she said. "It hits hard."
And student Shannon Rioux-Smith said he expected most students wouldn't come to class at all today.
Teen slain in front of mom outside Hamilton high school
"You hear about it in other places in Hamilton. But your school? In the backyard? That's very alien," he said.
Hamilton police investigating serious assault outside secondary school
The Hamilton police forensics team was on the scene to take more photographs at the back of the school. Inside the school, grief counsellors were available for students.
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In a news release, Hamilton police said that around 6 p.m. Monday, another male youth was arrested, interviewed and released unconditionally once his "involvement in the investigation was established."
Manny Figueiredo, director of education at the Hamilton-Wentworth District School Board, was at the school Tuesday morning.
Four teens facing murder charges in connection with stabbing outside Hamilton high school
"Enrolment is a little lower today. Some parents have said, 'I just want to keep my child home,'" he told CBC News. "Many have come in because they want to talk and make sense of this act of violence."
Alice Smith, who has lived just down the road from the school for the past 14 years, said she was sitting in her front sunroom with her husband on Monday afternoon when five teens came around the corner, with a car following close behind.
"She said she tried to save him, but she just couldn't do it," Smith said. "She was very upset. She couldn't stop crying."
Teenager dies after serious assault outside Hamilton high school: police
Kandace Brenn, who also lives in the area, said she knew the victim, and he had been a visitor to her house. She described him as a "sweet, quiet kid" who kept to himself.
She said her niece called her to give her a lift. The niece wanted Brenn to drive her and her best friend to the Hamilton General Hospital emergency room, where the victim had been taken. Both girls are students at the high school, and her niece's friend was the victim's girlfriend, said Brenn.
Det.-Sgt. Stever Bereziuk said there was a "relationship" between the teen and the accused, but said he couldn't provide more detail about it because to do so would "speak to the evidence" of the investigation.
"As soon as I got to them, I just started breaking down, 'cause I knew it was bad — the look on their faces. She couldn't even breathe."
When asked Tuesday about whether or not the teen was bullied, he would only say police believe they have a "pretty good picture" of what was going on between Selvey and the people who allegedly attacked him.
In the car on the way to the hospital, she said the friend described finding the victim unconscious and bleeding. Later, she got a call from her niece that he hadn't survived.
"She doesn't know how to cope. She doesn't know how to help her best friend through it," said Brenn.
Boy, 14, fatally stabbed in front of his mother outside Hamilton school
Brenn said the victim had a rough start to high school, with bullying and being picked on. But she did not know if that had any connection to what happened Monday.
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