The Empty Chair by Jeffery Deaver

Renowned criminalist Lincoln Rhyme faces his ultimate opponent: a kidnapper and murderer dubbed the Insect Boy. But Rhyme is in for a surprise when he learns that catching a criminal is one thing...and keeping him is another. Now Rhyme, in North Carolina to undergo risky spinal cord surgery, finds himself hunting a ruthless killer in the heart of a southern swampland -- and going head-to-head with his protégé, Amelia Sachs, in a rivalry that tests the limits of both their expertise and their love.