Thanks to behind-the-murder shows like ''CSI,'' there now exist legions of normal folks-turned-armchair forensics experts. (Duh, Matlock. The stippling on that GSW indicates an execution-style shot.) But there's still room for amateur sleuths to learn a few things from Dr. Bill Bass, the forensic anthropologist who started the University of Tennessee research facility affectionately known as ''the Body Farm.'' In Death's Acre, an account of his years studying corpses and the clues they leave behind, Dr. Bass uses his folksy humor and extensive knowledge to share the gory details of his day job. And, boy, does he give up the goods -- like the time he took a murder victim's head home and boiled the decomposed flesh off her skull to help identify her. Dr. Bass also kindly offers helpful hints: ''Most people don't realize how hard it is to consume a body by fire. It sounds like an easy way to get rid of a murder victim, but it's not.'' Duly noted, Doc.