Penance

In Penance you follow four girls as they try to live their lives after a finding the body of their friend murdered while out playing with them one day. Not only do they have to deal with survivors guilt they also have a threat from the girl's mother looming over their heads.

There are six chapters to this book, each chapter tells the story of one of the girls from the lead up to the murder and on to years later when the statute of limitations is about to run out, with the fifth chapter being dedicated to the dead girls mother and then finally the conclusion. You get to see how Emily's murder affected each of their lives and how each girl tries to fulfill the promise to Emily's mother to either find the murderer or complete an act of penance to her satisfaction.

Each girl offers a unique perspective to Emily and her murder and they all end up in drastically different situations, so it doesn't make the story feel repetitive even though they're technically all telling the same story.