Watching violence in movies or in TV programs stimulates the spectators to imitate what they see much more than if seen live or on TV news. In movies, violence is filmed with perfect illumination, spectacular scenery, and in slow motion, making it even romantic. However, in the news, the public has a much better perception of how horrible violence can be, and it is used with objectives that do not exist in the movies.
Steven Spielberg, in an interview by the Brazilian magazine Veja (1993), cited in Awake! magazine, 1993, 3/8, article: Watching the World.