An in-depth, detailed rundown by veteran TV and print journalist Jeffers of the workings of the Behavioral Science Unit (BSU) at the FBI's National Center for the Analysis of Violent Crime in Quantico, Va.--the same unit that's featured in The Silence of the Lambs. Readers of the Harris novel will be interested to learn, however, that the BSU studies, profiles, and investigates not only serial killers like Hannibal Lecter but also serial rapists, serial child molesters, mass murderers, and terrorists/assassins. Each type of criminal gets its own well-researched chapter here, but the focus--other than a long section devoted to the FBI's investigation of the Iowa explosion--is on serial killers, with a careful combing of the cases of many brand-name maniacs: The Boston Strangler, Son of Sam, The Night Stalker. However, Jeffers begins with a little- known case, that of a serial killer ``trolling'' for hookers, including ``Precious,'' in the Washington, D.C., area. Following BSU superagent John E. Douglas as he examines evidence, Jeffers explains that, to Douglas, ``a crime scene was regarded not as evidence of what had been done but as a symptom of the aberration of the person who did it''--allowing agents to induce a psychological profile, usually highly accurate, of perpetrators: When caught, Precious's killer fit the BSU profile hand to glove. A capsule history of violent serial crime and of the BSU follows, with much criminal fact and lore as well as a chilling recap of the BSU's extensive interviewing of ``violent criminal offenders.'' Jeffers concludes with a quick survey of how the media have treated serial killers, and a note on the likely future of the FBI's program. Very thorough on BSU methodology and criminal psychology, but a close look at the psychology of BSU agents themselves would have deepened the narrative. Nonetheless: lively, informative, and timely.