Forensic archeological investigations are integral to a diverse array of situational contexts, but the singular objective these various operations accomplish is one of recovery and resolution—recovery of the physical evidence and eventual resolution of the legal issues.

Forensic archeological investigations are conducted in three general stages: reconnaissance, survey, and excavation. Reconnaissance is performed in order to locate the site of interest to investigators. This process can be carried out in a variety of fashions, with the three most common being walking/ visual searches, the use of cadaver scent locating dogs, and the use of geophysical detection instruments such as ground-penetrating radar, magnetometers, and resistivity meters. Walking/visual searches may be done in a number of patterns particular to the terrain, projected size of the area of interest, or other factor; however the objective of these searches is a common one—to identify any surface evidence present and thereby establish a potential site perimeter or extent. Cadaver dogs are an obvious asset when investigators are searching for an interred individual and can most often identify a location of interest with great accuracy. Geophysical detection reconnaissance operates on the premise that anomalies in the ground (such as disturbances caused by burials) provide data signatures divergent from pristine, undisturbed soil, thus providing a clear indication of areas of prior activity that need to be investigated.

Upon the identification of the site of interest and its extent, the next stage is to survey or map this area. This can be conducted in many different ways, with two common approaches being tape and compass maps and the use of a total data station. Tape and compass maps are conducted with a tape measure and bearing compass—horizontal measurements and directional readings are taken for points of interest within the site in order to create a plan map or bird’s eye view of the area. Using a total data station (digital data recorder that records point locations in the X, Y, and Z planes) provides the opportunity to record data in greater detail with a high degree of ease. These XYZ coordinates can then be input into a GIS (geographic information system) in order to allow investigators to process and manipulate the data to create a detailed site map. Mapping of the site surface is a task that needs to be completed not only prior to excavation, but also upon the discovery of significant finds as digging proceeds in order to capture a geo-referenced representation of the various stages of recovery to accompany photographs.

Once the site has been located and mapped, excavation may begin. Comprehension of the concepts of superposition and stratigraphy are key during the course of an excavation in order for investigators to preserve the proper provenience (location within the site) and context of remains, personal effects, other pertinent evidence as well as of any samples (botanical, entomological, soil, etc.) that are taken. It must be stressed that provenience and context are extremely important— without these, no piece of evidence can be properly fitted into the puzzle of the site to arrive at a clear, complete representation of the deposition act, the events surrounding it, and the identification of individuals involved.

From: Forensic Archeology in Criminal and Civil Cases by Micaela N. Obledo