'Star pupil', 13, behind Serbian school massacre made a gun pose with his fingers before shooting

The 13-year-old ‘star pupil’ who confessed to shooting dead eight of his classmates at a school in Serbia was allegedly bullied and made a gun pose with his fingers in his last Instagram post before carrying out the massacre.

Kosta Kecmanovic, 13, opened fire on his screaming classmates inside their classroom in the Vladislav Ribnikar Elementary School, killing seven girls and a boy – all below the age of 14.

A security guard, identified as Dragon Vlahovic, in his early 50s, was also killed…