Anyone who decides to contribute to the search for missing persons must be prepared: they must know what rules regulate it, how searches are carried out, what are the things to do and those to avoid. He must therefore have a scientific background of academic training in the forensic field.
Geolocation and territorial analysis (so-called spatial analysis) are essential to be able to extrapolate information on the movements of the missing. In this regard, the approach known as geographic profiling is very useful to have a geo-referenced trace on the map not only of the place of disappearance but also of all the sightings (of people, cameras, etc.), of all the possible places that the missing person usually frequented and possibly of the places that could be used to hide. This approach allows to create predictive models, with a good approximation, of future movements or in any case reduce the search area.
In cases where the implications of the investigations lead to think of the death and possible concealment of the corpse of the missing person, these methods provide for a territorial analysis by remote sensing, or using satellite images, from aircraft or drone to be able not only to analyze the territory of the disappearance remotely but also to be able to highlight through images with different chronology (ie before and after the disappearance) any changes in the territory through a series of multispectral filters such as infrared, NDVI (vegetation growth index), NDWI (reservoir change index) or LiDAR in wooded areas.
These preliminary analyzes performed on the computer are necessary to prepare to go to the site and allow a considerable narrowing of the research field favoring a more precise and focused autopsy investigation of the places. Such reconnaissance can help in the creation of an additional map that helps to reduce field research even more. This map is the so-called RAG map (Red Amber Green) or traffic light map in which the sectors in which the presence of a concealment of a possible corpse is very, on average and unlikely.
In the restricted areas deduced from the aforementioned analyzes, it is possible to carry out a further control by means of geophysical surveys (in this case by georadar) which in a completely non-invasive and repeatable way allows to have a fairly accurate interpretation of the subsoil. In the light of the results of all the methodologies used and illustrated so far, in an absolutely non-destructive/invasive way, it is possible to have a very limited area of research with a high probability of identifying the investigative target.
At this point only a stratigraphic/scientific excavation (which follows the archaeological procedures) and not arbitrary (bulldozer or by improper means) allows to collect all the evidence necessary to properly reconstruct the scene of the crime and have, possibly, a relative chronology drawing the necessary considerations. The use, therefore, of techniques ranging from macroscale to microscale, identifying all the peculiarities and information useful for research, reducing the use of human resources, the possibility of limiting intervention times and the ability to operate in difficult and / or dangerous conditions for rescue teams, are within the economic reach of everyone today.
A simple GIS (Geographic Information System) platform can safely collect all this information and develop predictive models not only in the case of missing persons but also for other crimes (such as theft, robbery, violence, etc.), highlighting the areas at greatest risk as is already the case in many countries such as the Netherlands thanks to the NFI. Identifying patterns of spatial behavior is extremely important as the information can be used by police forces to pinpoint likely areas of research. This will help reach missing people before they suffer physical damage and save valuable police resources, time and money. Therefore, it is desirable to make efforts to collect and record this type of information with the greatest possible accuracy.