It Should Have Been You by Lynn Slaughter

Clara Seibert still lives in her twin sister, Moura's, shadow, even though Moura was murdered five months ago.  Clara carries on day by day as the ghostwriter of an advice column for her high school newspaper, knowing that her sister's killer is still at large. Writing helps her forget the horror of the pictures that will forever be in her mind from the night she found her sister murdered.  The column is her safe place.

When Clara receives threatening emails from the anonymous account, she begins to relive the nightmare all over again. Not only do the emails imply that Clara will be next to die, they clearly state that she is the one that should have died instead of Moura.  "It should have been you...but soon."

The investigator in charge of her sister's case still thinks that Clara killed Moura out of jealousy over Moura's success as a brilliant pianist.  Her father is terrified and her mother is simply absent in grief over Moura's death.  Feeling certain that she cannot trust anyone to help her, she is determined to find her sister's killer on her own to put a stop to the threats and never-ending fear.

This story is well-written and engages the reader from the beginning.  The angle continually changes while Clara questions several people of interest, so the story never gets boring. When the story seems all wrapped up in a neat bow, the author throws in an unexpected twist that grips the reader until the end.

The one disappointment for me was the lack of closure of an important relationship in the story.  I would recommend this book solely for entertainment.  I was happy to finally read a new YA book that was more entertaining than politically charged.  Fun mystery/thriller!