Secret Diaries Series by Janice Harrell

From the creators of the bestselling Vampire Diaries and The Secret Circle here's a trio of perfectly packaged teen thrillers. The first novel centers on a young girl's discovery that the exciting, rich boy she's fallen in love with is involved in the mysterious disappearance--and possible murder--of another girl.

After discovering, to her horror, that her boyfriend and his friends are responsible for a girl's death, Joanna agrees to cover up the truth, until one of the group turns to blackmail.

Swearing secrecy to the group that is covering up the facts about Laurie and Casey's "accidental" deaths, Joanna and her boyfriend, Penn, are horrified to discover that her diary has been stolen by a killer who is out of control.