A 15-year-old former pupil killed one employee and injured two others at a Polish primary school on Thursday wearing a helmet-mounted camera, the second school stabbing in two days, possibly in response to an internet challenge, authorities said.
A 37-year-old woman who worked as a caretaker had died in the latest attack, which took place at around 9am local time in Leszczydol-Nowiny, northeast of Warsaw, officials said.
On Wednesday, a 19-year-old wounded 10 people including himself at another…



