Forensic Medicine and Human Identification

Just as identification of a living individual allows for contacting of next of kin if necessary, or processing their medical/legal needs, identification of a deceased person serves many purposes. Family can be contacted, allowing for the grieving process to begin and permitting arrangements for disposition of the body. Correct identification of a decedent also allows for accurate documentation of the death (i.e., filing of the death certificate) and permits the deceased’s financial and legal issues to be addressed, including the settling of the estate, filing life insurance claims, and probating a Last Will and Testament.

Death investigation is greatly enhanced by knowing the identity of the person.
A medical and social history can be obtained from the decedent’s family and friends, and medical records can be obtained from local hospitals/clinics.
Witnesses may be interviewed to determine when the decedent was last seen.
The decedent’s residence/property may be examined for further information.

In 2007, the Office of Justice Programs, Bureau of Justice Statistics, determined that there were approximately forty-four hundred unidentified medical examiner/coroner cases in the United States, with approximately one-fourth of those cases remaining unidentified after one year. Thus, establishing the identity of an unknown person is a large concern for forensic scientists. The establishment of identity is a combined duty of law enforcement and the forensic scientist/pathologist. The efforts to establish identity ultimately result in one of the following identification categories: positive, presumptive, or unidentified.

This chapter will address the various methods for establishing the identity of an individual/remains from the perspective of a forensic pathologist (medical examiner); thus, the methods discussed will mainly refer to those used for deceased individuals. Many of the principles discussed, however, can also be applied to living individuals who require identification.

1.2 Human versus Nonhuman
The identification of remains begins with establishing that the remains are human. This may be obvious, as in the case of an unidentified person found by the side of a major highway, but it may also be more complex, as in the case of a single bone recovered from the neighborhood dog park. The most common items that require delineation between human and nonhuman are ecomposed bodies, particularly skeletons, and fragmented or dismembered bodies.
For skeletonized remains, most major bones can easily be assessed by a forensic pathologist or anthropologist for species identification, though smaller bones may require further analysis. Dismembered body parts can also be difficult to assess, especially if decomposed. Portions of eyes, ears, fingers, and toes, as well as complete feet, hands, extremities, and thoraces, ay be recovered. Often radiographs can be used to delineate species, the classic example being that of a bear claw resembling a decomposed human hand. Radiographs would reveal multiple sesamoid bones in the paw that are not present in the human hand. Small animals may resemble human fetal remains. Not uncommonly, and especially during hunting season, entrails will be uncovered and the question is again, are they human or nonhuman?
Examination of the remains will often yield the answer by the presence of multiple stomachs (e.g., the deer has four), the gastric contents (e.g., grass, leaves), or the anatomy of the organs themselves.
If anthropologic and radiographic examinations fail to differentiate the species, DNA analysis can be performed. Forensic scientists can extract the DNA and look for the hTERT (human telomerase) gene on chromosome 5, which is specific for humans.

1.3 Establishing Identity
Once the remains have been identified as being human, a number of methods can be employed to determine identity.
The most common means for establishing a positive identification are visual, fingerprint, DNA, and dental comparison. The latter three are often referred to as the scientific methods and will be thoroughly discussed in forthcoming chapters, and therefore will not be discussed here. In addition, a presumptive identification can be established by numerous methods addressed below, which is often very useful for future utilization of DNA or dental comparison. Although numerous databases exist for the comparison of fingerprint and DNA evidence to establish identity, without a comparison sample, both of these methods are useless. Similarly, dental identification is not possible if no antemortem dental records can be found. The techniques discussed in this chapter can be used either alone or, more often, in combination to establish the presumptive identification of an individual, allowing for either dental, DNA, or fingerprint information to be obtained and compared.

1.4 Visual Identification
Visual identification is perhaps the most commonly used method of identification and is used to establish both positive and presumptive identification.
Visual identification is used in cases of automobile accidents or a witnessed collapse and a family member or friend tells the police or emergency medical personnel, “This is John Smith.” Law enforcement/medical personnel take the identification as truth, that this is who the witness proclaims. However, visual identification is one of the least reliable forms of identification and an be fraught with error. Witnesses/family may be under duress at the time of the incident and make an innocent mistake (“Well, it looked like Uncle Bob”). The family/friends may refuse to examine the remains, may simply glance at the remains rather than truly examining them, or may deny that the remains are those of their loved one as an emotional defense mechanism.

Witnesses/family members may purposefully incorrectly identify the decedent for either financial gain or other personal reasons.
Comparison of the deceased to a photograph, whether from a driver’s license or personal photo, is another form of visual identification. Visual identification is also employed in public notice campaigns where an individual’s photo or a facial reconstruction is broadcast on television or flyers, asking anyone who recognizes the photo/sketch to contact authorities to assist with possible identification.

In many cases, however, the body may not be able to be identified visually. The changes of decomposition, including drying of the mucous membranes, bloating of the soft tissues, discoloration of the skin, and skeletonization, may obscure/obliterate features. The face may also have sustained injuries that distort the features, severely limiting visual identification, including trauma or burning.

1.5 Circumstantial
The circumstances of death can often assist in identifying a person. The location where a person/body is found in itself can provide helpful clues. If found in a domicile, one can establish who lives there, or if found in a vehicle, investigators can track down the owner. Personal papers, mail, medications, and other items may be present at the location of the remains and may be reviewed for a name or other information (e.g., address, age). The clothing a person is found wearing can be examined for size, brand, or any laundry marks. Clothing can also be compared to accounts from family and friends as to what the decedent was last seen wearing. Jewelry should be examined and can be compared to family/friends’ descriptions, or it can be analyzed for personalization or traceable information (e.g., a class ring, an engraved locket). Personal effects with the body can also provide information, such as a cellular telephone, business cards, phone numbers, and keys.
Eyeglasses and contact lenses can be examined and compared to the known history of a person.

1.6 External Characteristics
Many people have identifying characteristics on their bodies themselves that are unique enough to establish identity. Things such as body habitus, height, weight, eye color, sex, circumcision, stature, hair type (e.g., curly/straight, long/short), microscopic hair structure (e.g., oval, round, flat), and skin pigmentation can all be helpful attributes. Scars and tattoos are commonly used as identifying characteristics, especially when they are distinct in either nature or location, for instance, a scar from a burn or an injury, a keloid, or a unique tattoo. Birthmarks or nevi (moles) are often distinct and can be used for identification. The presence, location, and number of piercings may also be helpful.
Occupational stigmata, though more commonly used decades ago, may also be revealed during an external examination. Subungal hematomas involving the great toes are common in dancers and athletes. Onycholysis can be seen in occupations that require carrying heavy objects, or in musicians and typists. Inflammation around the fingernails can be seen in hairdressers and gardeners. Contact with chemical agents may cause certain types of skin rashes. Calluses can occur on the hands and feet in certain occupations. Blue scars are often seen in coal miners due to carbon dust entering skin lesions.
Small burns on exposed skin may result from steel or foundry work.

1.7 Internal Characteristics
An autopsy examination is commonly performed on unidentified bodies, and in most jurisdictions is required by law to be performed on such bodies. The presence or absence of certain diseases can be helpful in establishing identity, especially when medical records are available. Diseases such as coronary artery disease or cancer may be present. Conditions like cholelithiasis or nephrolithiasis (gallstones and kidney stones) may have been diagnosed prior o death. The absence of organs, due to either surgery or congenital malformation, can be distinctive. While surgeries like appendectomies, hysterectomies, and cholecystectomies are too common to be distinctive, splenectomies, nephrectomies, or other procedures may be more useful. The presence of suture material may also indicate a previous surgical procedure. Implanted devices, such as pacemakers or defribillators, can often be traced through the manufacturer to the recipient. Findings at autopsy may assist in determination of age, including the presence of arcus senilis (opaque ring surrounding the cornea), the presence of osteophyte formation along the vertebral bodies, and the closure of growth plates. Pulmonary anthracosis may indicate the decedent was a smoker, though significant anthracosis may be seen in coal miners who do not smoke. Other inhalational lung diseases may also provide information bout the decedent’s occupation, such as silicosis (sandblasting, quarrying, stone cutting) and asbestosis (mining, textile workers).
A complete toxicologic evaluation should also be performed, even if not related to cause of death. The presence of certain medications or illicit chemicals may give information regarding lifestyle or possible medical facilities.

For example, if methadone is present, treatment facilities could be contacted or helpful information.

1.8 Radiographs
Radiographs are commonly used to establish identity when antemortem radiographs are available for comparison. In such cases, unique structures (e.g., cranial sinuses, sella turcica) can be compared. Identifying characteristics, such as a broken bone resulting in a malunion or varus/valgus deformity of a long bone, can also be used. Radiographs may reveal the resence of foreign material, such as old bullets or shrapnel, or surgical hardware, which can often be traced by a serial number on the device through the manufacturer to the recipient.
The presence or absence of growth plates or the extent of osteophyte formation may establish whether the remains are those of a younger or older individual, though forensic anthropology can often be more specific.

1.9 Anthropology
Forensic anthropology is most commonly used in the cases of decomposed or skeletal remains. The techniques utilized can indicate sex, race, ancestry, and stature.
A brief description of forensic anthropologic discussion follows in Chapter 8. The determination of stature is performed by measuring the long bones and utilizing multiple formulae developed for such a purpose.

Pelvic morphology is the best indicator for determining sex, as a woman’s pelvis is wider and shallower with an obtuse subpubic angle and an oval inlet.
The cranium can also be used to attempt to determine sex, if the pelvis is not available. A male’s skull tends to have a receding forehead, prominent brow ridges and occipital protuberance, and a large mastoid process.
If the skeleton is that of a younger person (less than thirty years), growth plates can help delineate age as the plates tend to close (fuse) at certain stages of development. As the person becomes older, age-related changes can be seen, such as osteophyte formation, calcification of the cartilaginous margins of the ribs, and wearing changes of the symphysis pubis. These changes, along with fusion of the cranial sutures, can be used to approximate age.

Ancestry becomes more and more complex as our society becomes more global and less isolated. Traditionally, anthropologists acknowledged three races: Caucasoid, Mongoloid, and Negroid. However, with intermingling of the races, distinct separations are often difficult. For instance, Hispanics often show any combination of the three race categories. Ancestry determinations often combine the classic features of each race, and computer programs are used to determine a likely lineage. Classically, Negroid crania show wide nasal orifices, round/oval orbits, and alveolar prognathism; Caucasoid crania have narrow nasal orifices, parabolic palates, and rectangular orbits; and Mongoloid crania often demonstrate elliptical palates, complex cranial utures, and square orbits.

When a cranium is present, facial reconstruction can be performed in addition to anthropologic analysis. The forensic artist is given the anthropologic data of approximate age, sex, ancestry, and physical attributes (e.g., small, athletic). The morphologic properties of the cranium are combined with the artist’s presumptive rendition of the soft tissue features, including eye color and hairstyle, to generate either a sketch or model of how the deceased looked in life. A photo of the resulting face can then be distributed to the media or local community in an attempt to find a witness who can identify the individual. Unfortunately, the resulting image does not always accurately approximate the deceased and may end up misdirecting the investigation.

Anthropology and facial reconstruction are rarely used alone to establish identity. They are crucial elements in establishing presumptive identifications that can then be combined with DNA or dental analysis for final, positive identification.

1.10 Sources of Comparison
Most commonly, from the circumstances of death, the forensic pathologist or investigating agency has a supposition of who the unidentified person may be and the family is often contacted to provide information (such as doctors, hospitals visited, clothing, tattoos) in order to establish a positive identification.
Should no materials be present to allow for such a presumptive identification, several databases exist for comparison of unidentified persons to missing persons. Again, since DNA and fingerprints will be discussed in a forthcoming chapter, the Automated Fingerprint Identification System (AFIS) and the Combined DNA Index System (CODIS) will not be discussed here, only mentioned, as they are among the databases used in the attempt to identify persons.

The oldest system is the National Crime Information Center (NCIC) Missing Person File, created in 1975, and the Unidentified Person File, created in 1983. Investigative agencies can submit identifying characteristics to the Criminal Justice Information Services (CJIS) Division’s Intelligence Group of the FBI, which oversees the databases. The information is then crossreferenced against known missing persons to find similar, matching cases. If similar cases re found, the investigating agencies are able to contact each other to obtain the information required to establish a positive identification. Unfortunately, not all unidentified persons or missing persons get placed into the system.

The FBI has also launched the VICTIMS web-based database in an effort to make the unidentified human remains portion of the NCIC database accessible to the forensic identification community to assist identifying remains.
Its purpose is to provide a “…role-based access to enter and search records of the unidentified, while allowing the public access to information that may assist in the identification of these individuals.”
However, as of 2009, the database is still in its development/data collection stage.
In 2007, the National Institute of Justice began funding the National Missing and Unidentified Persons System (NamUs).

This system consists of two databases: unidentified decedents and known missing persons data. Phase III of the NamUs database project is scheduled to occur in 2009, which will link the two databases allowing for comparison of unidentified remains to known missing persons. The database will be searchable by and accessible to medical examiners, forensic scientists, law enforcement, and the general public.

Private organizations may assist in identifying victims of crime, such as the National Center for Missing and Exploited Children, which can be contacted and may provide information helpful in identifying decedents.
Various other programs are available for instances of natural or other disasters through agencies such as the Disaster Mortuary Operational Response Team (DMORT), Federal Emergency Management Agency (FEMA), and National Transportation Safety Board (NTSB).

1.11 Methodology for an Unidentified Person/Body
The examination of unidentified persons should be meticulous, well organized, and methodical. Extensive photographs should be taken, including photos of all distinguishing characteristics-eyes, tattoos, scars, etc.-as well as any and all personal property, which should be inventoried and catalogued. In cases of deceased individuals, a full autopsy should be performed, thoroughly documenting all disease processes, presence and absence of organs or tissues, organ weights, and detailed and accurate descriptions of all pertinent positive and negative findings. Full body radiographs should be taken and reviewed. Fingerprints, dental charting, and a DNA sample must be taken on cases, where possible.
One unidentified person can require a great deal of organization and documentation to establish identity; however, in cases of natural or man-made disasters, organization is a necessity. All bodies/body parts, including any and all corresponding property, must be kept separate and uniquely marked.
Each body requires the same examination outlined above in an orderly and organized manner, yet it must be conducted as rapidly as possible. In addition, mass disasters may include the need for decontamination of the bodies, a media contact person for the central dispersion of information, as well as a centralized record-keeping system.

It is important to remember that identification is an extremely important task that allows for the grieving process of loved ones to begin as well as a thorough investigation of the death. Identification can only be accomplished through the meticulous examination of the remains. Though there is always the pressure to rush, one must not sacrifice quality for the rapid answer, as the quick answer is often not the correct one.

References
1. FBI VICTIMS database http://www.victimsidproject.org/login.aspx
2. National Missing and Unidentified Persons System (NamUs). http://www.namus.gov.

Suggested Reading
Haglund, W.D. 1993. The National Crime Information Center (NCIC) Missing and Unidentified Persons System revisited. Journal of Forensic Sciences 38:365-78.
Knight, B. 1991. The establishment of identity of human remains. In Forensic pathology, chap. 3. New York: Oxford University Press.
Spitz, D.J. 2004. Identification of human remains. Part 1. Diverse techniques. In Spitz and Fisher’s medicolegal investigation of death, ed. W.U. Spitz and D.J. Spitz, chap. 4th ed. Springfield, IL: Charles C. Thomas.
Weedn, V.W. 1998. Postmortem identification of remains. Clinics in Laboratory Medicine
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