A zinger debut introduces Cat Austen, of Ocean City, N.J., an entertainment writer who is the only sister of six brothers and the widowed mother of two small kids. On assignment interviewing shock-jock radio duo Jerry and Tom, Cat gets too closely involved in the pair's promotional gimmick. Called "The Perfect Murder," the stunt involves Jerry's playing a corpse at remote sites; after a series of clues are given, the first person to guess whodunit wins. But then Jerry is fatally shot the night he tries to tell Cat ``a shocker.'' As she works on the suddenly refocused story, Cat must run interference between her overprotective brothers (five of them are cops; the other is a priest) and widower Lt. Vic Cardenas, who is in charge of the case. She isn't surprised to learn that Jerry, who consciously offended everyone he could in his public life, did the same in private; she just has to figure out which of his targets shot him for it. Rubino's warm and feisty Cat, who is constantly fighting for independence from her large family, shines in this fast-moving first novel.