Police investigating the murder of 15-year-old Thomas Devlin have made a fresh appeal for information.
Thomas Devlin was stabbed to death
The detective leading the case said they need more evidence if they are to charge anybody with the killing in north Belfast.
Thomas, 15, was stabbed in the back five times as he and two friends walked home along the Somerton Road, on 10 August 2005 after buying sweets.
Nine people were questioned but no-one has been charged with the murder.
Police said that more than 900 statements have been taken in relation to the killing and more than 60 properties searched.
Detective Superintendent Simon Barraclough, who is leading the investigation, said police had suspects but not enough evidence to convict them.
"I believe that there are people out there who still hold crucial information that would convict the killers of this child," Mr Barraclough said.
"I believe that the murderers left the scene, I believe they went away and actually destroyed their clothes, I believe they got rid of the murder weapon that was actually used to stab young Thomas and I believe they spoke to people about what they did.
"These people are still in the community and they haven't spoken to the police.
"They need to come forward and they need to speak to us about what happened."
Det Supt Simon Barraclough wants public's help
Thomas's mother, Penny Holloway, said the lack of convictions had been frustrating for the family.
"I think it is terrible that there are people out there who know the two people who did this and yet they don't feel that they want to come forward," she said.
"Thomas's murder was particularly brutal - he was jumped on from behind and stabbed five times.
"I think it's important for all of us that these individuals are put away for this crime."
Thomas's 18-year-old friend was injured in the attack, but not seriously. A 16-year-old boy managed to escape.
Thomas, a student at Belfast Royal Academy, was a talented musician who played the horn at school.