A 598-page document contains posts suspect Payton Gendron allegedly wrote on a site called Discord. Authorities say the document shows how he plotted the attack for several months. WATCH FULL EPISODES OF WORLD NEWS TONIGHT: https://abc.com/shows/world-news-tonight WATCH WORLD NEWS TONIGHT ON HULU: https://bit.ly/3iQLwPp #BuffaloShooter #SocialMedia #Discord #WorldNewsTonight