Murder's pretty bad—but Bambi's mom gets murdered, and that movie was still a solid "G."
The violence in Chinatown elevates it to a PG, and the occasional F-bombs kick it up to a PG-13. But what really makes this flick a hard R is the rape and incest. That's just icky. No one likes thinking about rape and incest…but after seeing Evelyn scream, "She's my sister and my daughter!" it's hard to think about anything else.