It is no easy task to write a good crime novel that features a youthful sleuth. Too young to drink, to drive, to wander the mean streets or to have a wasted past, young sleuths also have parents lurking in the background, ever ready to assert their authority about meals and bedtimes. Full credit, then, to Beth Montgomery for overcoming these obstacles and writing a gripping mystery. In Murderer’s Thumb, fourteen-year-old Adam Statkus and his mother have relocated from the city to the country in yet another effort to escape an abusive husband and father. Rosemary Statkus, jittery and terrified, is in no state to assert any authority over her son, beyond instilling in him the necessity of keeping a low profile. That becomes harder to maintain when Adam finds the decomposed body of a teenage girl buried in a silage pit. Then he stumbles upon a hidden diary that contains clues to the murder. Others would also like to get their hands on it. The diary is a McGuffin, and the climactic exposure of the murderer a bit hammy, but Adam is a tough, credible and appealing protagonist, and the evocation of a close-knit farming community and the build-up of tension are terrific.