His father said that, for the last six months, he felt he hadn't known his son.
And now, he never will again. Rachid Chaiboub's boy, 17-year-old Tarek, was gunned down in a Burngreave barber's shop on Friday, just after a week after being stabbed seven times.
When a gunman walked into the salon where Tarek was having a haircut, the injured teenager pulled out his own gun. It was like a scene from a gangland movie.
What had happened to Tarek in those last few months of his life?
His father said his boy changed; he stopped listening to him.
"I didn't know about my son after that. He was in a different world," he said.
There comes a point in many a teenage boy's life when he's suddenly a sullen stranger to his parents. He turns his back on their influence and guidance and looks for it from his peers or his hero figures.
But eventually most boys grow up and out of it; they come back to you unscathed.
In the other world that Tarek entered, the heroes seem to have been from street gangs and rap music. Tragically, there was no way back.
He thought he was a tough, cool little nut, an invincible "souljah." His death proved that he wasn't; he was just a naive kid. How someone like that gets their hands on a gun, how they afford it, why they want it and how they hide it, are mysteries to people like us.
But they are the questions that need answering if we are to get anywhere near stopping kids from killing other kids they've had some stupid fall-out with - and anyone else who happens to get in their way.
Rachid had some words of advice for other parents; "They need to know who their children's friends are, whether they are bad or good."
And that, as Mr Chaiboub knows, is the hardest thing.
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The full article contains 342 words and appears in Sheffield Star newspaper.