DNA Identification in Mass Fatality Incidents
Robert Shaler
The degree of fragmentation should determine the minimum fragment size. Because of the extreme fragmentation of remains of World Trade Center victims, the minimum was approximately the size of a thumb.
Policies also need to be established at the beginning of the effort that define “minimum fragment size” for DNA testing. A policy that has as a goal “all remains tested” may mean that many fragments may fail to yield results. In this situation, the DNA effort would take longer and be more costly—and, although families would be more likely to receive more of their loved one’s remains, they may be unprepared for the fragmentary condition of the remains or the length of time it takes to identify them.
Decisions must be made regarding the minimum fragment size on which identifications will be attempted, the number of attempts that will be made to identify each fragment, and the statistical threshold that must be met before results are conveyed to the ME. These decisions are fundamental to a laboratory’s strategic planning. Planning— including preliminary meetings between the laboratory director, the forensic anthropology staff, and the ME—is critical, because it allows each entity to understand the perspective of the others in the emotionally charged environment following a mass fatality incident.
From the laboratory director’s perspective, the minimum fragment size—typically, 1 to 10 centimeters—should be based on three criteria:
- maximizing the probability that all victims are identified;
- recognizing the emotional needs of the victims’ families and friends; and
- providing forensically relevant information.
Defining the acceptable minimum fragment size affects every aspect of the identification effort: how remains are collected at the incident site, how they are processed in the morgue, the number of samples that ultimately appear on the DNA analyst’s workbench, and the likelihood of a successful DNA profile.
Go to Next Section: How difficult will it be to identify everyone?
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