THE POPULATION OF COLMA, California, is heavily skewed toward the dead. The ratio of those below the ground to those breathing air is about twelve to one. My mom is buried at Cypress Lawn in Colma, and so is Yuki’s mom, and now Kelly Malone and her brother, Eric, were burying their parents here, too.

  It would appear to the casual observer that I was alone.

  I’d put flowers at the base of a pink granite stone engraved with “Benjamin and Heidi Robson,” two people I didn’t know. Then I sat on a bench a hundred feet from where the grass-scented breeze puffed out the tent flaps where the Malones’ funeral was in progress.

  My Glock was holstered under my blue jacket, and the microphone inside my shirt connected me to the patrol cars at the entrance to the cemetery. I was watching for a gangly kid named Ronald Grayson, or someone else who looked out of place, a stranger with a penchant for torture and murder. It didn’t happen every time, but some killers just had............