156 Forensic dentistry
the National Crime Information Center (NCIC), which includes descriptive
information for analyzed unknown remains as well as missing individuals.
Many states operate databases and missing persons clearinghouses for their
own jurisdictions. Still other databases specialize in a particular demographic
segment of the national population, e.g., the National Center for Missing and
Exploited Children (NCMEC).
In recent time, databases utilizing DNA technologies and powerful search
engines have been created for a number of populations. These include the
Armed Forces DNA Identification Laboratory (AFDIL) and the Combined
DNA Index System (CODIS). The latter contains reference samples consist-
ing of nuclear and mitochondrial markers from relatives of missing persons
as well as mitochondrial and, usually, genomic markers from unidentified
human remains. The CODIS system utilizes biological profile and dental
information submitted with skeletal samples from unknown remains as
metadata. When the system detects a possible hit, i.e., a match between a
reference sample and a set of remains, it may be weak (i.e., achieve a less than
desirable level of statistical certainty), owing to the badly degraded condition
of the remains. Or, the system may find several possible matches either for
the same reason or because the original reference samples were taken from
individuals who were not first-degree relatives of the decedent. Given several
possible matches, or one weak one, the anthropological and dental profiles
are used to parse the list or to strengthen the weak match.
Presently, a number of problems reduce the effectiveness of databases.
Most do not interact with others because of incompatible formats, propri-
etary issues, or matters of confidentiality and access between jurisdictions
and entities operating the various databases. The most important limita-
tion on the use of any database in identifying unknowns, live or dead, is its
inclusiveness. The best chance a missing individual or set of remains has of
being identified resides in whether these have been submitted to a database
with as much accompanying information as possible. Obviously, unidenti-
fied remains must have an accurate analysis. A significant problem arises
because of the differing skill levels of those who initially develop the profile.
If the unknown remains are sufficiently complete and “fresh” to allow accu-
rate determination of sex, age, ancestry, and stature visually, then a report
from a pathologist may be sufficient for use as critical metadata. However,
when remains are incomplete, fragmentary, degraded, etc., the biologi-
cal profile should be completed by an experienced forensic anthropologist.
Errors in the assignment of ancestry or age, improper dental charting, or
other misinformation entered into a database will likely result in false elimi-
nation of a correct identity match, i.e., “garbage in, garbage out.” Likewise,
DNA reference samples should be from the closest possible relative of the
missing individual. When bone or dental samples from unknown human
remains are submitted to the CODIS database, these should be accompanied