Jodie Chesney's father has spoken of his struggle to forgive his daughter's killer.
The popular student had been with friends in a park when she was stabbed in the back on the evening of March 1.
In a case of mistaken identity, Jodie, 17, was an innocent victim of "casual violence" in the drug-dealing world, jurors heard.
Jodie's family shouted "yes" at the Old Bailey as a jury found Svenson Ong-a-Kwie, 19, and a 17-year-old boy guilty of murder after less than six hours of deliberations earlier this month.
Speaking outside court, Jodie's father Peter Chesney said: "The two people in the park I'm over the moon about."
Now Mr Chesney has spoken to The Daily Mail about life after the trial.
The grieving father said that he has talked to other parents who have lost their children to knife crime.
One piece of advice many of them offer is to forgive your child's killer.
"I said, 'How can you do that?' and they replied that they did it for themselves, that the hate was eating them up," he said.
"Well, right now, I hate Jodie's killer. I don't want him to drink beer, to see the sun rise, to love, because Jodie isn't going to have any of that. I want him to suffer, to rot in a dark place.
"But I also don't want to be consumed by hate. I've lost half of me, I'm half the person I was. I want to try to get some of me back."
He has now set up the Jodie Chesney Foundation, which aims to reach young people before they start carrying knives.
Ong-a-Kwie, 19, and a 17-year-old boy have been convicted of Jodie's murder, while two co-defendants Manuel Petrovic, 20, and a 16-year-old boy were cleared of murder.
The 16-year-old and 17-year-old cannot be named because of their age.
The two killers will be sentenced on November 18.
