250 Forensic dentistryis established it can be changed. Experience has shown that it is easier to
decrease the area of control than to increase it, making it wise to establish a
generous perimeter in the opening phases of the operation.12.4.3 Grid/GPSOnce the perimeter is established, a system to define the different areas of the
crime scene is needed to allow recovery teams to easily record the exact loca-
tion of the evidence they find. In the past it was found that simple grid sys-
tems worked well with flat scenes, similar to an airplane crash on land. Grid
numbers on maps could be marked as evidence was recovered. It has been
found in recent incidents that when dealing with collapsed buildings and
water settings, simple grids fail to give adequate information about elevation
and return points of reference. Global positioning system (GPS) technology
has been employed in some situations, allowing not only a positional record,
but also a very accurate way to return to a specific area and, if necessary,
establish and document elevations of points.
12.4.4 Security and Safety
Security of the site is always a concern. An established perimeter will aid
with this. A control system needs to be established early in the incident to
allow access to the crime scene to only authorized personnel. Badge systems,
periodic changes of codes, and photo identification have all been used to
prevent unauthorized access. Fingerprint scans are now easy to implement
and monitor with computer systems. These systems could be used for access
control as well as computer system logins. A security officer and an established
security protocol should be the focus areas for all security-related questions.
The protocol should be required reading for all workers, who should avow
that they have read and understood the policies in a signed document as a
part of their indoctrination into the operation of the incident.
Safety should be among the most important aspects in the management
of a mass disaster site. There may be a large number of injured and dead
individuals as a result of the disaster. There is no justification for adding to
those numbers with responders who do not follow safe practices. A safety
office should be created, and as in the security section, there should be a
safety protocol developed, understood, and adhered to by the workers to
prevent more injuries and loss of life. The debris field of an airplane crash
or the resulting devastation of a detonation of a bomb in an urban setting
yields situations and materials that are physically dangerous and potentially
contaminated with dangerous substances. The safety officer and the person
responsible for hazardous materials (hazmat) should coordinate and estab-
lish the safety of the site before responders enter the area. The safety office