Housen explained that Ground Penetrating Radar (GPR) could reveal clandestine grave sites up to twenty feet below the surface. It wasn’t foolproof, but with careful measurement of the areas to be searched, and by marking known objects already in the ground such as utility lines, buried storage tanks, or foundations long covered over with dirt, something unusual an “anomaly” might be seen and evaluated.

The old white barn where Ty and Neil used to play in the rafters, where Leo Garcia had temporarily imprisoned young women, was long gone now. An asphalt county road S. 251st Street had been built two to four feet over the barn’s concrete floor.

And...