Dressed in a dark grey checkered suit, the boy appeared emotionless as the verdict was delivered at 3.22pm, after around four hours of deliberation.
Alesha MacPhail’s body was found in woods on Bute on July 2 last year, hours after she was reported missing from the house her father shared with his parents on the island, where she was staying for part of the school holidays.
In a statement released after the verdict Alesha’s mum, Georgina Lochrane, said: “Words cannot express just how devastated I am to have lost my beautiful, happy, smiley wee girl.
“I am glad that the boy who did this has finally been brought to justice and that he will not be able to inflict the pain on another family that he has done to mine.
“Alesha, I love you so much, my wee pal. I will miss you forever.”
The MacPhail family said: “We can’t believe that we will never see our wee angel Alesha again. We miss her so much.
“We hope that the boy who took her from us is jailed for a long time because of what he has done to our family.
“Alesha may be gone from our lives but she will always be in our hearts.”
Detective Superintendent Stuart Houston, Senior Investigating Officer, said: “I welcome today’s verdict and hope that it will bring some comfort to the family and friends of little Alesha McPhail who have been through the most horrific ordeal.
“Throughout the police investigation and this trial, Alesha’s family have shown incredible bravery in the face of the most appalling circumstances.
“Alesha’s senseless and barbaric murder shocked the small community on Bute and people across Scotland. The effects of her death are still being felt today.
“Crimes such as this are extremely rare and I am glad that we have been able to get justice for Alesha and her family.”
Len Scoullar, Councillor for the Isle of Bute and Provost of Argyll and Bute, said: “Words cannot begin to explain the pain and anguish being felt by everyone in our very caring community here on Bute. Alesha will never be forgotten by the people of Bute, and my thoughts are with Alesha’s loved ones at this most awful time.”