This had a solid idea: a pair of twin girls invented a triplet sister when they were kids, and now dress as this fake sister as a way to go out with unsuitable boys. But now the fake sister's ex boyfriends are showing up dead, and it's one of the real twins bring accused of murder. 
 So, a promising mystery-thriller. But the main character is an idiot. Seriously dumb. Like, asking friends what on earth she should do with this evidence that could exonerate her, and everyone is mystified by the idea that one could do something with evidence BESIDES lay a trap for the potential killer, putting a friend in grave danger. WHY. "The cops won't believe me! I have to solve this myself and catch the killer!" even though this puts you at the scene of yet another crime. WHAT. 
 A good premise, and could have been a good story, but ugh there was too much stupidity to take this book at all seriously.