Joaquin Phoenix's dark, hyper-realistic portrayal of the Joker is causing backlash before the movie even opens. Titled "Joker," Phoenix stars as failed comedian Arthur Fleck, who ultimately becomes the comic book villain. But some worry the movie could inspire violence. Several victims of the 2012 mass shooting in Aurora, Colorado, are expressing their concerns in particular. Twelve were killed and dozens more injured in the massacre at a screening of "The Dark Knight Rises."