Evidence at a crime scene may be destroyed, altered, or transported by animal behavior, including scavenging. Animal sign can be misleading or be a valuable source of information.

When bone is found at a site, it is critical to differentiate between human and nonhuman bone, as well as materials easily mistaken for bone.

Many different things can disturb the vegetation at a crime scene. Branches can be broken by a car or truck or even by digging or crashing through bushes. Date of disturbance can be determined. Layers of leaf litter might have accumulated on the grave and can be counted. Roots growing into the body can be aged. Small pieces of plant material found in a grave can be identified and perhaps tie the suspect to the crime scene The botanist must have a working knowledge of plant taxonomy, plant anatomy and micro-anatomy, succession, history of area and many other subjects. Ideally the botanist will have access to the site at the beginning of the search because otherwise, important information could be lost.

The impact of water on a burial site can be important in terms of atmospheric moisture, surface flow and drainage, soil moisture content, and groundwater flow and drainage. Water may also impact a site with regard to its chemistry. For example, precipitation patterns and surface flow may relate to the transport of evidence on the surface and the the type of vegetation and wildlife present. Variations in soil moisture may be indicative of a disturbance (such as a burial site) and could impact decomposition. Ground and surface water may also be important to the distribution of scent in an area. A hydrologist is usually needed to interpret these water related aspects of a potential burial site.

A meteorologist is able to give specific information for a search area regarding the microclimate and general weather before, during and after the body’s presumed disposal. The conditions before and during body disposal could affect where is body may be located. Microclimate at a site is also useful for interpreting decomposition and other evidence at a site, such as plant type and growth stage. Later weather events may result in erosion or flooding, which could cover or transport evidence.

Digging a grave disturbs the geology. Soil horizons are disrupted and mixed, material from depth is moved to the surface. Rocks are re-oriented, porosity and compaction of soil is changed. Soil and sediment may be transferred to the perpetrator and tools. A geologist uses knowledge of mineralogy, petrology, stratigraphy, structure, and geomorphology to help recognize and interpret disturbances.

Forensic Investigations involve locating, identifying, collecting, documenting, preserving and analyzing evidence. One aspect of this process may involve locating clandestine (hidden) evidence that is often concealed in the subsurface. This task may be aided by information gained through informants, witnesses, psychics and/or suspects. Resultant searches may be time consuming, resource intensive and frustrating. Any nondestructive methods used to reduce time spent on searches and to increase the probability of locating clandestine evidence can be very useful to law enforcement agencies. Remote sensing methods include geophysical surveys, which are based on determining contrasts (anomalies) within the subsurface. Geophysical surveys are time-efficient and cost effective, and are used by NecroSearch to screen areas and locate anomalies consistent with the evidence being sought, whether it is a weapon or a body. Many geophysical surveys used by NecroSearch can work in water.

Locating clandestine grave sites often involves multiple disciplines such as archeology, geology, geophysics, botany, entomology, remote sensing, etc. Merging and analyzing the field observations and measurements obtained by these different disciplines has been historically problematic. This is especially true given the time constraints typically associated with high profile searches. Fortunately, computer methods developed for natural resource exploration have been adapted by NecroSearch to search for hidden graves. These programs are executed on laptop computers directly in the field in order to quickly isolate targets for subsequent excavation. The foundation for these methods involves the superposition of an imaginary grid over the project area. Numeric values, corresponding to observations and measurements, are assigned to the individual cells within these grids. Separate grids are created for each type of data set. For example, grid "A" might contain soil conductivity measurements while grid "B" might represent the density of a particular plant species within each cell boundary. These grids are then statistically analyzed and combined in order to identify atypical regions called "anomalies". These anomalies define the exploration targets that merit additional examination (e.g. excavation).

Cadaver dogs are valuable for detecting human remains. Although NecroSearch has members who are cadaver dog handlers, we do not have our own dogs. Whenever possible, we suggest that arrangements be made for a cadaver dog search.

Identification of insect species and observations of their distribution at a site can indicate how long ago a body was disposed of and the conditions at the time. Correct collection and preservation is essential.

In addition to employing the individual methods mentioned here, we may organize line searches in suspect areas.

Excavation Methods NS uses archaeological techniques to excavate. Grid construction, sifting, scene mapping ad recording are some of the techniques we use to preserve and demonstrate the spatial relationships among any evidence found.