Det Insp Lynn Donnelly said: “Our thoughts first and foremost are with Jack’s family and friends, and all those affected by this incident.”
She added that there would be a police presence in the area while the investigation continued.
Ch Insp Mhairi Crawford said: “We know the loss of a young life is felt within our communities, and I would like to reassure the public that we are working tirelessly to fully investigate what happened.”