A knife found near where a 15-year-old boy was fatally stabbed was not the murder weapon, police have said.
Thomas Devlin was stabbed five times
Thomas Devlin was stabbed as he and two friends walked along Somerton Road in north Belfast on 10 August.
Detectives said the knife, found by a resident cutting a hedge at the rear of his house off the Landsdowne Road on Monday, was not used in the attack.
However, they said it was not ruled out of the ongoing inquiry. Police issued a fresh appeal for information.
Thomas had just bought sweets from a nearby shop when he was stabbed in the back five times.
His 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.
A number of people detained for questioning about the murder have been released without charge.