The family of Yousef Makki - the 17-year-old grammar school student who was stabbed to death in Hale Barns - will launch a £100,000 fundraising campaign to fund a civil case over his death.
The 'Justice for Yousef' campaign will be launched in Manchester tonight.
Yousef's family say they now 'wish to instruct legal professionals to investigate the opportunity to put forward a civil case in relation to the death of their son and brother'.
Yousef's family said the costs of taking such an action have been initially estimated at £100,000.
They said a 'minimum' of £20,000 was needed to secure the court transcripts from the criminal trial of two teenagers held earlier this year. As of 6am on Tuesday (October 15), £12,317 had been donated.
Yousef, a Manchester Grammar School pupil from Burnage, wanted to become a heart surgeon.
He bled to death after being stabbed in the heart in Hale Barns, Trafford, on Saturday, March 2.
The teenager who inflicted the fatal stab wound - who can now be named as Joshua Molnar after he turned 18 - was cleared of murder and manslaughter following a four-week trial on the grounds of self defence.
He is serving a 16-month detention and training order for possessing a knife and perverting the course of justice, charges he admitted.
A second 17-year-old - 'Boy B' - is serving four months for possessing a blade, but was cleared of perverting the course of justice.
He cannot be named for legal reasons.
In a statement, Yousef's family said: "
The family said they wanted Yousef's death to be re-examined and that there were 'many unanswered questions'.
In August, the family said they were 'disappointed', but would 'fight for justice' after the Attorney General's office refused their request to refer the sentences of the two convicted teenagers to the Court of Appeal.
Yousef's sister said the decision showed the government wasn't 'tough on knife crime' and the sentences 'sent the wrong message about knife crime'. Alongside former chief crown prosecutor for the north west, Nazir Afzal, and anti-gang and gun campaigner Erinma Bell, Yousef's mother, Debbie Makki, is also due to speak at the summit.