Planning Charlie's Confession

Today Beth and I started to write the voice over for our film. We are writing it as if Charlie is writing to her diary as later on, the diary is used as Charlie's confession.
We wrote the voice over that goes at the start to set the scene and introduce the characters and then we went on to write the second voice over which happens after Charlie has a meeting with Scarlett Reed (her teacher) regarding her diary. In our film, Scarlett finds the diary and sees that Charlie has this obsession with her, and then realises that she can manipulate Charlie and use it to her advantage.
We wanted to have a voice over as not only is it a convention of film noir, but it also creates interest for the viewer as they will want to keep watching to find out what happens at the end. It also makes the ending of Charlie killing herself seem more surprising and haunting as the audience realises that they are essentially hearing a voice over by a girl who is dead.