To the outside world, he was an introverted loner, but online the Prague University gunman was not shy about sharing his sick fantasies to kill. David Kozak used online platform Telegram to muse on massacres and mass murder, while also boasting of his plans to carry out a school shooting, according to Czech media. He said his Telegram channel would be a “diary” of his life “before the shooting”. “I want to do school shooting and possibly suicide,” the 24-year-old wrote in one chilling post, before adding: “I always wanted to kill. I thought I would become a maniac in...