WARNING: If you haven't seen the movie, I'm going to ruin it for you!
GBG's little girl is missing and presumed kidnapped. What really happened is mommy accidentally overdosed baby, trying to insure she'd sleep soundly so mommy could go hang out with some guy. Mommy lies and lies, but eventually leads cops to the body. (This movie could have been only 15 minutes long if they'd edited out the "f" word. I've never heard it used so many times in any other movie.)
This movie wouldn't make Casey afraid of calling the cops in (and I don't believe for one nanosecond she was afraid of calling the cops because CAYLEE might be harmed) but it COULD give her some ideas about how to handle an accidental death.