Here we have Scottoline's sixth offering, and no exception to a repertoire that only improves as it enlarges.  In this book, (Ms.) Bennie Rosato herself enjoys the limelight occupied by her associates Mary and Judy from other stories (although they both appear with small parts herein); so it's nice we finally get to learn much more about the principal herself.  Moreover, the author baits our hook in chapter 1 that the murder defendant, Alice Connelly, may be Bennie's unknown identical twin - and appearances at a minimum seem convincing.  We're kept in limbo on this question until chapter 41 (of 44), adding a great deal of suspense to a story otherwise already pretty compelling.  Even the book's title vacillates in our minds as first a clue then a red herring re the twin mystery.  But while we get the twin question settled finally by DNA (one way or the other), unlike so many tales of this genre, several plot elements are left to further pondering at the end.  In fact, that the book ends on a situation hardly totally settled may speak to perhaps the ethical issues the Publisher often asserts is part of Scottoline's appeal.