The Thai teen behind a deadly school shooting outside Bangkok had an air gun confiscated by a teacher last year and had watched violent content online, police said on Sunday, as the government promised new safety protocols for schools.As investigations continued into Friday’s rampage, where a 14-year-old boy allegedly shot dead his grandparents at home before killing another six people at his school before turning the gun on himself, police said the boy had used social media to learn how to...