What is This Book Title??

Question

There is a book series and it has girls with the names of

hannah

ari or arianna

alli

and alli goes missing and they get notes signed with the letter A.

Answer 1

Pretty Little Liars

Answer 2

Pretty Little Liars series by Sara Shepard

Answer 3

That book is called Pretty Little Liars by Sara Shepard.  

Answer 4

"Pretty Little Liars"

That was a good book :) Wasn't it about a girl that was really popular, but disappeared, and no one knew where she went? Or maybe they all did something and bullied a girl, and she disappeared? I can't remember. It was something about the girls doing something to the one that disappeared... Also, in that book, wasn't there something about finding a skeleton in the back of the neighbors (neighbor to one of the girls, possibly the one that was telling the story, if it was written in first person) yard, which was the missing girls old house?