What events is Kate trying to solve?

Post Mortem involves the brutal rapes and slayings of five women throughout the Richmond area. Each woman is stalked, strangled, raped, and asphyxiated. There seems to be no discernible pattern in the killings, no common thread between the victims. As Chief Medical Examiner, it is Dr. Scarpetta's job to learn as much as possible from the victims' remains in hopes of catching the killer.