

A chilling video posted to social media captures a 15-year-old student opening fire with a handgun at a private school in the northern Mexican city of Monterrey on Wednesday, wounding a teacher and three other students before killing himself.
The teacher and and two other students at the bilingual American School of the Northeast appeared to take bullets in the head from the .22 caliber pistol.
The assailant, who was being treated for depression, then killed himself.
Another student suffered a non-life-threatening gunshot wound to the arm.
The video, apparently from the school's surveillance camera, shows a female teacher collecting papers from students.
The youngsters are seated at their desks when the boy opens fire with a pistol from a sitting position, hitting a boy in front of him, who immediately slumps to the ground