A judge told the youngsters it was one of the saddest cases he had ever been involved in and spoke of his disbelief at the ‘gratuitous’ violence meted out by the teenagers during the attack.
Leeds Crown Court heard the robbers, aged 15 and 16, excelled at school, were from loving families and had never been in trouble before.
On the day of the attack, the 15-year-old had just received a letter of congratulation from his teacher at being allowed to sit his GCSE maths exam early.
James Keeley, prosecuting, said the youths put on skeleton masks during the robbery at the shop on Armley Ridge Road, Armley, Leeds, on November 13 this year.
The shopkeeper had a knife pressed against his throat and was repeatedly punched in the face before being kicked as he lay on the ground.
The pair stole cigarettes and cash from the till but were caught soon after the attack. They both pleaded guilty to robbery. Lawyers for the pair described the youngsters as bright students who had high career ambitions and had been looking forward to going to going to university.
They also said the youngsters had a close network of friends and did not drink or take drugs.
The court was told they had both acted out of character and were sorry and ashamed of what they had done.
Judge Christopher Batty imposed a 12 month detention and training order upon both youngsters.
He said: “This is one of the saddest times I have had in court.
He added: “Sadly we have too many young men come before this court, but not grade A schoolboys who have never been in trouble.
“People need to understand that if they go and mete out violence to a shop keeper in order to take his property, the courts will not tolerate it.
“I’m afraid I can’t do anything but pass a sentence of detention. I do this with the heaviest of hearts but I do it because it is my public duty to do it.”