The Edge of the Crazies by Jamie Harrison

Perched at the foot of Montana's Crazy Mountains, Blue Deer is a small town boasting an uneasy mix of longtime residents and hotshots from both coasts looking to possess their own piece of the Big Sky. Local sheriff Jules Clement manages the town's tensions fairly well...until someone blasts a hole in screenwriter George Blackwater's office window--and in George himself.

As more of the town's prominent citizens start turning up dead, the pressure on Jules keeps rising. It starts to look like this rookie sheriff may not survive the next election...if he lives to see it.