The teenager who was killed as he walked home with friends in north Belfast was Thomas Devlin.
Thomas Devlin had spent the evening playing computer games
The 15-year-old boy had just bought sweets and was walking home along Somerton Road, when he was stabbed five times in the back.
A 16-year-old boy managed to escape - but an 18-year-old was also hurt, although not seriously.
Two men and a male juvenile have been arrested in connection with the teenager's death.
Thomas's parents said the whole family was devastated by what had happened.
They said the police had told them that they currently had no motive for the attack.
Thomas's mother, Penny Holloway, said her son was "a lovely, good-natured, bright and kind-hearted boy".
Police cordoned off Somerton Road after the murder
"For his life to be snuffed out like this is unbelievable. We're just devastated," she said.
Thomas, a student at Belfast Royal Academy, was a talented musician who played the horn at school.
He spent Wednesday night playing computer games at his home in the Somerton area.
One of his friends planned to stay over and they decided to go out for food but were attacked on the way home.
"It's come to something when a boy can't even walk up the street to his own home," she said.
It is understood that police officers were called to the area at about 2350 BST.
Parish priest Father Sean Emerson said the boy's family was still in a state of shock.
"I was with them this morning, just on a pastoral visit and they are finding it very difficult to come to terms with it and, I suppose, they are just suffering from a total and absolute numbness at the moment," he said.
North Belfast MP Nigel Dodds said the killing had stunned the local community.
Mr Dodds said: "The death of anyone in such circumstances is deplorable but it is particularly shocking when the victim is so young.
"The whole community will be shocked and appalled at what has happened and our sympathies go out to the family circle at this time."
Alban Maginness, SDLP assembly member for north Belfast, also said the murder was "deeply shocking".
"I think of the devastation that will come to his mother and father and the rest of the family. Everybody in this district will be shocked by it."
Detectives in North Queen Street have appealed for anyone with information to contact them at 028 9065 0222.