Postmortem by Patricia Cornwell

Under the leafy cover of night in Richmond, Virginia, a human monster moves undetected, leaving a gruesome trail of stranglings that has paralyzed the city. Medical examiner Kay Scarpetta senses the worst: a deliberate campaign by a brilliant serial killer- a 'Mr.Nobody'-whose signatures offer precious few clues. With an unerring eye, she must call on the latest advances in forensic research to have a chance at unmasking the maniac. But this investigation will test Kay like no other, because it's being sabotaged from within-and someone wants her dead.