According to Harlan (2004), "Sample retention is problematic not only because of these individuals' innocence, but also because of the resulting availability of sensitive genetic information and the lack of legislative and jurisprudential protections guarding release of the information" (p. 179). This point is also made by Beecher-Monas and Garcia-Rill (2006), who caution that modern DNA identification techniques can be used to extrapolate far more than just an individual's identity, but with some profound social consequences involved. These authors write, "DNA identification testing has become commonplace in the courts, transforming the criminal justice system, demonstrating innocence, and identifying perpetrators. Already it is clear that DNA testing will be used as a way of predicting which medical treatments will be effective. With predictive medicine becoming a reality, surely predicting human behavior cannot be far behind" (emphasis added) (Beecher-Monas & Garcia-Rill, 2006, p. 301).
1. Fragment sizes. According to Gonzalez and his associates (2006), "DNA analysis is the gold standard for identification of human remains from mass disasters. Particularly in the absence of traditional anthropological and other physical characteristics, forensic DNA typing allows for identification of any biological sample and the association of body parts, as long as sufficient DNA can be recovered from the samples. This is true even when the victim's remains are fragmented and the DNA is degraded" (p. 9). The minimum fragment size needed for reliable DNA testing (usually, 1 to 10 centimeters) should be based on three fundamental criteria: (a) maximizing the probability that all victims are identified; (b) recognizing the emotional needs of the victims' families and friends; and - providing forensically relevant information (Gonzalez et al., 2006). These authors add that, "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" (Gonzalez et al., 2006, p. 14).
2. Decomposing DNA. According to Gonzalez et al. (2006), the extent to which human remains are fragmented or degraded serves to determine the value of DNA analysis in the identification process; decomposing DNA does not yield the same results as less degraded material.
d. How does the analysis get proper resource and funding? Because of the enormous expense involved in administering DNA identification testing in cases of mass casualties, the Federal Emergency Management Agency (FEMA) remains the principal source of federal funding for mass fatality incidents (Gonzalez et al., 2006). There are other sources of funding available as well for DNA identification testing, though. According to Lyon (2002), the 1994 Crime Control Act provided financial support for the CODIS and other initiatives by providing for a coordinating nationwide DNA data bank systems. A report, sponsored by the Justice Department to implement the Act, also provided an award of $8.75 million in grants to states and city crime agencies to improve their DNA testing capabilities (Butterfield, 1996). As a result of that incentive, all fifty states adopted laws requiring specified offenders to provide blood samples for forensic DNA testing (Lyon, 2002).
Other sources of funding for DNA identification testing are described by Carroll (2007), who reports that individuals in Missouri that request such tests in an attempt to exonerate themselves from criminal charges may be liable for such charges if the tests confirm their guilt; moreover, they may be liable for additional time added to their existing sentences for filing frivolous petitions (because they apparently were aware of their guilt prior to demanding such testing) (Carroll, 2007). This author recommends that all states enact such an approach to prevent an abuse of DNA identification resources (Carroll, 2007).
III. DNA management.
a. Source of DNA samples. One of the most advantageous aspects of using DNA identification in cases of mass disasters is the fact that DNA samples can be virtually anything people touch or otherwise come into contact with. According to Nelkin and Andrews (2002), "A wad of spit, a spot of blood, a semen stain, or a single hair is all that is necessary to create a DNA 'fingerprint.' DNA profiles can be extracted not only from blood or sperm at a crime scene, but also from objects touched by a person's hands, and from saliva used to lick stamps. From a tiny sample of body tissue, a forensic laboratory can use an autoradiogram to create an image consisting of a cluster of horizontal bands that form a pattern resembling a bar code" (p. 94). Likewise, Milunsky (2001) reports that, "Substances successfully mined for DNA in criminal cases have included blood specks, semen stains, hair roots, nasal mucus, saliva, and skin found under the nails of a victim, at a bite site, under a licked stamp or on an envelope, on an instrument of murder, or at other sites. A twenty-five-year-old vaginal swab taken for semen was successfully used in one criminal prosecution" (p. 84). Finally, as Harlan (2004) notes, "DNA is present on any item touched by an individual; it exists in hair, which is shed in public, and in saliva, such that it may be gathered from any used cup, straw, or spoon" (p. 179). A comprehensive listing of potential sources of DNA samples is shown in Table 1 below.
Potential Sources of DNA Reference Samples.
Personal items (also known as direct references)
Biological samples include blood stain cards, blood stored for elective surgery, pathology samples, semen samples, and extracted or "lost" (adult or baby) teeth. Personal use items include hairbrushes, toothbrushes, razors, unwashed undergarments, and used personal hygiene items (e.g., sanitary napkins).
Personal items are the most precious of all samples (including human remains) because they are so scarce. Personal items allow for the simplest type of DNA matching: direct comparison; however, sole use by only the victim can be difficult to ensure. Before reporting an identification, the lab must verify that the DNA from the personal item belongs to the victim. This is done either administratively or through DNA interpretation. Personal items require forensic analysis conditions (extraction, quantitation, etc.).
Biological relatives (kin)
Samples are collected from biological relatives. Kinship samples are typically collected using buccal swabs.
The relatives' biological relationship to the victim largely determines the utility of the sample (e.g., parents provide better reference samples than cousins). Distant relatives can be useful if there are many of these types of relatives in kinship analysis, but the analysis of the pedigree can become very difficult. Although biologically unrelated to the victim, the surviving parent of a missing person's biological child can assist in determining an identification. Sometimes the relative does not know his or her true relationship (if any) to the victim. The lab must verify (administratively or through DNA interpretation) the relationship before reporting an identification.
Previously identified human remains
Human remains identified using other modalities. For example, DNA from a torso identified through a medical examination or a unique tattoo may be used as a reference sample to identify other remains fragments; or well-characterized DNA profiles from other fragments may be useful to associate samples.
Like personal items, previously identified remains can be directly matched to unknown samples. Single teeth have proven to be unreliable reference samples because they are easily misidentified through non-DNA modalities.
Source: Gonzalez et al., 2006, p. 6.
A summary of the types of DNA samples using in the Twin Tower attacks of September 11, 2001, is shown in Figure 1 below.
Figure 1. Types of Samples From the World Trade Center Response.
Source: Gonzalez et al., 2006, p. 59.
b. Using Identification Number on the site. To help facilitate on-site processing of DNA and kinship data, Gonzalez and his colleagues (2006) recommend having an information technology professional available. One of the software tools that can be used for this purpose that was also used in the DNA identification of the Twin Towers attacks was from the aforementioned CODIS. According to Gonzalez et al. (2006), "Two of CODIS' four files -- " the Missing Persons and Unidentified Human Remains Index (CODISmp) and the Reference Samples from Personal Items and Family Index -- " allow the search of DNA profiles. The use of mtDNA profiles as a screening system is facilitated by the introduction of the CODISmp system. Although designed for missing persons, the system may be used to search for DNA profiles of mass disaster victims" (p. 48). These authors adds that, "The typical strategy for accessioning reference samples is to assign each victim a case number and add reference samples as submissions under the case. The case number is important because it represents the victim's family…