CAMELBACK FALLS

Though he’s still entitled to wear the uniform and carry the badge and gun, David Mapstone is 20-plus years away from being a real cop. These days he’s a semi-cop, a former history professor working for the sheriff’s office in Maricopa County, Arizona, sifting through the dust of old unsolved cases in the hope that a fresh look might work some kind of magic. It’s a dilettante’s job, but dramatic change is just around the corner. The swearing-in ceremony for newly appointed county sheriff Mike Peralta is ended violently by a bushwhacker’s bullet. Peralta, Mapstone’s longtime friend, is rushed to the hospital barely clinging to life. To his astonishment, Mapstone learns he’s become the politically expedient acting sheriff, charged with holding the department together until the county fathers find somebody better. With his serious criminal-catching days so far behind him, no one expects Mapstone to go after the shooter. No one, that is, except Mapstone, for whom necessity is the mother of reinvention. Once again the steely-eyed law-enforcement officer, he rises to the challenge. Aided by Deputy Lindsay Faith Adams, the “star of the cybercrimes task force” and incidentally his girlfriend, he follows a twisted trail to dark and unsettling places, among them his own half-forgotten history.

The plotting goes a bit shaky near the end, but Deputy Mapstone, firmly in the neo-noir tradition, is strong, suitably sensitive, and increasingly sympathetic: a notable improvement over his debut in The Concrete Desert (2001).