Video report by ITV News National Editor Allegra Stratton
The sister of grammar school student Yousef Makki - who died after being stabbed - has told ITV News his family want a re-trial following last week's self-defence verdict.
Jade Akoum said the family had suffered two "heart-breaking losses" after a jury cleared a teenager of murder on Friday.
The defendant, boy A, and another boy, 17, boy B, both from wealthy Cheshire families, were both cleared of all charges following a four-week trial at Manchester Crown Court on Friday.
The verdict has raised questions over race and privilege in the criminal justice system.
The Labour MP for Manchester Central, Lucy Powell sparked debate after she criticised the verdict. She wrote on Twitter: "You do have to ask if these defendants were black, at state school and from, say, moss side whether they would have been acquitted ..."
She told ITV News she stands by her comments saying there is "inherent racism" in the criminal justice system.
"The evidence shows us this," she said.
"The government's own race audit shows us this, the David Lammy review shows that those from black and ethnic minority backgrounds are much more to be harshly treated by the criminal justice system and get bigger, longer sentences."
But Ms Powell has been criticised by others for using one trial to make a sweeping political statement.
Nick Buckley from Mancunian Way, an antisocial behaviour reduction charity, told ITV News Ms Powell's words would have a negative effect on teenagers from deprived backgrounds.
"If you're a 13-year-old black boy now in Greater Manchester and you read that, you're going to be thinking 'wow, the government, the world, everyone's against me'. And that's not the case," he said.
"We're just giving these young boys another reason to opt out of society, to opt out of community because an MP has told them 'there's no point you trying now because you're young, you're black, you live in Moss Side'."
Yousef, from a single-parent Anglo-Lebanese family from Burnage, south Manchester, had won a scholarship to the prestigious £12,000-a-year Manchester Grammar School.
The 17-year-old was attacked in the village of Hale Barns, Cheshire in March this year. He was taken to hospital where he died a short time later.
His sister Ms Akoum told ITV News Yousef "was a caring and loving son and uncle, someone my own children see as the perfect role model."
She said: "We as Yousef's family are absolutely devastated by the verdict given on Friday.
"We have suffered heart-breaking losses twice now. Firstly in losing in Yousef and secondly now that no one has been found accountable for his murder."
The jury heard the stabbing was an “accident waiting to happen” as all three indulged in “idiotic fantasies” playing middle class gangsters.
Despite the privileged backgrounds of both defendants, they led “double lives”.
Calling each other “Bro” and “Fam” and the police “Feds”, the defendants and Yousef smoked cannabis, rode around on bikes, “chilling” and listened to rap or drill music.
They would post videos on social media, making threats and posing with “shanks” or knives.
Boy A denied murder on March 2, claiming he acted in self-defence.
He admitted perverting the course of justice by lying to police and possession of a flick knife.