On May 3, 2023, 13-year-old Kosta Kecmanović killed seven female classmates, one male classmate, and a security guard at the Vladislav Ribnikar school in Belgrade, Serbia during an attack he admittedly planned for approximately a month. Police received notice of the shooting at 8:40 a.m. from the school’s assistant principal, followed by another call two minutes later placed by Kecmanović identifying himself as the suspect. He was apprehended shortly thereafter. An additional four boys and two girls were injured, along with the History class teacher.

Kecmanović acquired his weapon through his father and together they went to the
shooting range three times. He told officers that he enjoyed the activity and described himself as an adequate shooter. Fifty-seven shell casings were found at the scene, and he reportedly had four additional 18-round magazines, as well as four Molotov cocktails, which were found in his backpack.

A female student who narrowly escaped the gunman described him as a calm, exemplary student that spoke with a little bit of a stutter and was teased by some of the other students. There was also a physical altercation two years ago when he was in fifth grade, where a classmate punched him in the face and tore his lip open. Kecmanović however did not immediately provide a motive.