Do u Like My Idea for this Story? Murder Mystery/Drama?

It was a good story, but there are some things I would change, maybe not have her go to school, that's just my opinion because a lot of books now are taking place in high school. Other wise I really liked it! I'm gonna take a guess, knowing I'm wrong... Since you used identical twins, maybe Casey isn't dead, maybe she killed her sister, vis vvis i don't know, just thought I would try...