DNA Identification in Mass Fatality Incidents
Non-DNA Data (“Metadata”)
Data, other than DNA profiles, that are collected about missing persons and reference samples are often referred to as “metadata.” Metadata about family reference samples—including family-member relationships (i.e., pedigree), data about the missing person, and autopsy data—are compiled in case folders. Metadata, combined with DNA test results, are used in the identification process. When these two data sets (metadata and DNA test results) fail to reconcile, the cause of the inconsistency must be resolved. This leads to delays in an ultimate identification, stress for loved ones, and increased work for analysts.
It is essential, therefore, that metadata management be given a high priority (see chapter 10, Sample Tracking and Management), and that a laboratory have in place a process for comparing data from different aspects of a DNA-based identification process.
In rare instances, metadata can appear to contradict the results of DNA testing, even when the DNA results from both the remains and reference samples are scientifically and statistically sound. Of course, metadata are more subjective than DNA-testing results, and the process of proving that a personal-item or kinship sample comes from a specific person or family can be cumbersome. But, ensuring the accuracy of the original metadata obtained from victims’ families—including the chain of custody of personal effects—is crucial.
