The huckleberry murders / Patrick F. McManus.

Enhanced descriptions from Syndetics:

Sheriff Bo Tully is the brand of western lawman who uses as much cunning and guile on the ladies as he does solving his cases. He's a man with a sense of humor and a hunch for the truth, which comes in handy when trying to capture killers and establish order in Blight County.As the novel opens, Sheriff Tully is following up on one of his famous hunches: he suspects the murder of local retiree Orville Poulson by his ranch caretaker, Ray Crockett, a sociopath with a criminal record. The only problem is, Tully has no evidence or body to prove that a crime has been committed--supposedly Orville is alive and well and cashing his Social Security checks from Spokane.Meanwhile, a far more alarming case emerges. Three young men have been shot, each in the back of the head, execution style, in a huckleberry patch on Scotchman Mountain, leaving behind no identification. With the help of confident and beautiful FBI agent Angela Phelps, Tully tries to connect the dots between Poulson's disappearance, the sudden spate of murders occurring in Blight County, and a big white pickup truck with dual tires causing havoc and crime. As the few potential leads are either killed off or prove nearly impossible to track down, Tully must follow his instincts to piece together the puzzle of who is doing the killing, and why. His suspicions lead him straight into a haunted swamp, along with Agent Phelps, his womanizing ex-sheriff father, Pap, expert tracker and good friend Dave, and mountain man Poke. A twisty case packed with murder and mystery,The Huckleberry Murdersis the most entertaining tale yet in this beloved series.