Two boys aged 13 and 14 have been charged with murdering a teenager.
Police said the youngsters, both from Chigwell, Essex, would appear in court charged with killing 14-year-old Jack Large.
Jack died after being stabbed in the back and head near his home in Grange Hill, Essex, on Friday.
A police spokeswoman said the two boys would appear before magistrates in Witham, Essex.
Earlier, Jack's mother told how the youngster had been involved in a school "anti-knife campaign" shortly before his death. Julie Maddison, 44, said Jack had warned other pupils about the dangers of carrying knives.
Mrs Maddison said several of Jack's friends had visited him in hospital and seen the effects of knife crime. "Jack has turned himself around in the past year," she said.
"He has been trying really hard at school and recently was involved in an anti-knife campaign with a view to educating his fellow pupils about the dangers of carrying such weapons."
She added: "It's not worth kids carrying knives on the streets and it's just got to stop. Those who were there at the hospital saw the effects of knife crime."
Police said Jack died on Sunday after undergoing surgery and being placed on a life-support machine.
Officers are trying to trace a number of teenagers seen on the Limes Farm Estate in Grange Hill at around the time Jack was attacked. The spokesman said police patrols had been stepped up in Grange Hill.
