Pretty Little Devils is complete!

A question that I have since I am now done with this book is will there be any consequences for the killer? I really don't like endings that don't explain everything. The person accused of killing three people has to remain in juvenile hall until she is eighteen, however, they have the wrong person. The real person at the end of the book was just reviled, but it just ended at that. Actually, she also added a threat which is as follows and that makes me wonder even more...

"It's not fair. But it's ok. I'm still kicking, and they'll get what they deserve. Matty will pay for interfering. They'll all pay, slowly. Painfully."