``Dealing with death on a regular basis has almost made me an expert,'' says Lauren Laurano, whose rueful remark has less to do with her private-eye status than with the high mortality rate among her friends. Latest example: Elissa Rosner, whose aunt, Ruthie Cohen, has been stabbed to death. It's the Granny Killer, say the cops, who then, changing their minds, focus on Elissa, the beneficiary of a big inheritance and no alibi. Convinced that her friends were born to be victims, not killers, Lauren gets Elissa to make a list of Ruthie's friends and guilelessly goes down the list ticking off the names, and sometimes the friends. Since there's not much mystery to Ruthie's death--the sixth friend, when Lauren finally gets around to ringing her doorbell, solves the case on the spot--there's plenty of time for Lauren's abandonment by her lover Kip, her guilty e-mail flirtation with Alexandra Thomas, her stalking by the psycho who started her on her law-enforcement career by raping her and killing her boyfriend 27 years ago, and Scoppettone's trademark vignettes of life in the Big Apple: sunny, pointless episodes that seem culled from the Times's Metropolitan Diary column. A persistent lack of ingenuity and urgency make this the weakest of Lauren's four cases to date (My Sweet Untraceable You, 1994, etc.).