Schools in northern state of Nuevo Leon implemented additional security checks of backpacks a day after a teenage student suffering depression shot three students and a teacher at a private school before killing himself.
The 15-year-old student pulled out a handgun inside a classroom at the Bilingual Colegio Americano del Noreste and began shooting, critically wounding three of his victims before turning the pistol on himself.
Officials report the gun used in the murders belonged to the assailant’s father.
