Video report by Adam Fowler.
The mother of a teenage boy who was stabbed to death 10 years ago has taken part in a new documentary aimed at preventing other tragedies.
Sarah Lloyd's son Kieran was 17 when he was attacked in Harehills, Leeds, in 2013.
His killer was jailed for life.
Ms Lloyd said her son's death continues to haunt her a decade later.
"My whole world was shattered then, not just mine. It had a devastating impact on the whole community," she said.
She was speaking ahead of the launch a new documentary, Cut Short: Fighting against Knives in the North.
In it, Ms Lloyd says: "You kill people's lives, you kill people's stories. You don't just take away the person and you take away the sunshine. You take away the heart.
"Mine never healed. I don't think it ever will."
She is calling for a ban on the sale of so-called zombie knives and machetes.
Also sharing his story in the documentary is Vilson Duarte-Dong from Leeds, an ex-offender who served time for using a knife in a gang attack.
Threatened with deportation by the Home Office, he told ITV News about the moment he knew he had to turn his life around."The first time I was told about my deportation, I rang a friend of mine and I was obviously upset.
"And he just said, 'Oh, well, that's it. What do you want me to do?' That's when I realised that they were around you because it benefits them at the time. As long as it doesn't that relationship ends."Vilson says there's no simple answer to stopping young people from carrying knives."It is about making sure people are healthy, mentally they have the right support around them," he said.
The documentary is available to schools. The makers hope to show it to a million young people by 2026.
Ms Lloyd added: "In an ideal world it would be in the national curriculum. I actually feel it's good enough to go in the curriculum.
"I don't think we'll reach every child that's carrying. I don't think there'll be some miracle cure and they'll suddenly all put their knives down. But just that change in mindset could make a difference. And save lives, including their own."