St. Louis authorities reveal that the 19-year-old gunman who killed a teacher and a student at his alma mater had a long history of mental health struggles, and his family tried to get help WATCH FULL EPISODES OF WORLD NEWS TONIGHT: https://abc.com/shows/world-news-tonight WATCH WORLD NEWS TONIGHT ON HULU: https://bit.ly/3iQLwPp #WorldNewsTonight #abcnews #schoolshooting #stlouis