What is this Movie?

It is about these girls that are in high school that for their friends birthday, the do a traditional thing and they stuff a huge jawbreaker into her mouth, tie her up, and put her in the trunk, then drive her somewhere. Then when they open up the trunk, she had died. So they take her body home and set it up so that it looks like a murder. Then a outcast girl from their school comes to the girls house to thank her for somthing, but sees her friends their while they are seting up the crime scene. So the leader of the group decides to take the girl under her wing and recreate her if the girl didnt tell. The girls name at first was fern, then they named her Vylette. (Violet) But then one of the original girls of that clique says that she doesn't think its right to do this. so they ditch her.then the leader of the group sets it up to look like a , without anyone else knowing. at the end, they set it up so everyone finds out about the murder. The Veronicas make a guest appearance. thnx!