GPR aids the investigation of recent and historical human activity.  It is used extensively to locate and delineate buried artifacts, soil disturbances, and hidden cavities. Buried Walls & Foundations GPR detects changes in subsurface conditions. Old foundations and buried walls which have no surface expression are readily visible on GPR records. These changes in material compositions modify the water distribution in the soil resulting in a GPR response. Numerous examples of area mapping with GPR have provided vivid pictures of the foundation layout of old buildings. Bodies & Graves GPR is widely used to locate buried bodies and grave sites. Headstones or markers for graves frequently get displaced over time. GPR is in steady demand to locate gravesites to correctly reposition marker stones. In addition, police searches for evidence regularly require location of shallow graves. GPR responds to both the buried remains and the disturbed soil associated with the burial. General, Historical & Human Activity GPR senses changes in soil composition, compaction and water distribution. Virtually any manmade disturbance of the soil will cause disruption of natural stratigraphy and cause redistribution of soil water. GPR measurements over areas can readily detect these changes, which may have occurred hundreds or even thousands of years previously. In addition, the technique responds to localized metal or rock objects buried in soils. This makes it a powerful tool for direct detection of buried artifacts or evidence in police investigations.