6.2 Identification of the Living, the Dead & Skeletal Remains

Why identification matters

Identity must be established before a death can be registered, an estate settled, insurance paid, a marriage dissolved by death, or a criminal case filed. The TOS lists "identification of human beings as a victim" first among the nature-of-medicolegal-cases topics. Expect items on mass disasters, decomposed or skeletonized bodies, and disputed identity of living persons such as age for criminal responsibility or for school and sports eligibility.

Identifying the living

Living persons are identified by:

• name, face and photographs;
• height, weight and build;
• color of skin, eyes and hair;
• scars, tattoos, birthmarks and deformities;
• occupational marks, such as calluses or stains;
• handwriting, voice and gait;
• fingerprints, which are the most reliable.

Age of a living person matters under the Juvenile Justice and Welfare Act (RA 9344 as amended by RA 10630). A child 15 years or younger at the time of the offense is exempt from criminal liability. A child above 15 but below 18 is exempt unless he or she acted with discernment. When birth records are missing, physicians estimate age from dental eruption, radiographs of ossification centers, and secondary sexual characteristics.

Primary identifiers

1. Fingerprints (dactyloscopy)

• Friction ridges form during fetal life (by about the fourth to sixth month) and persist unchanged until decomposition.
• No two individuals have the same ridge details, including identical twins.
• Pattern frequencies:

• Identification rests on matching ridge characteristics (minutiae: endings, bifurcations, dots, enclosures), not on pattern type alone.
• In decomposed bodies, prints can be recovered from degloved hand skin worn over the examiner's gloved finger, or from softened skin.

2. Dental identification (forensic odontology)

• Teeth resist fire, water and decomposition.
• The examiner compares post-mortem charting and radiographs with ante-mortem dental records: restorations, extractions, crowns, prostheses, root canals and anomalies.
• Teeth also estimate age, especially before about 25 years.
• Bite marks on victims or food can link an assailant, though their individualizing value is now treated cautiously.

3. DNA profiling

• Nuclear DNA short tandem repeat (STR) profiles individualize; only identical twins share them. Good sources are blood, buccal swabs, bone marrow, deep muscle, teeth (pulp) and dense bone such as the femur or petrous temporal bone.
• Mitochondrial DNA is present in many copies per cell and inherited through the maternal line. It is used for hair shafts without roots, old bones and degraded remains, and is compared with maternal relatives.
• Y-chromosome STRs follow the paternal line. They are useful in mixed samples from sexual assault and in comparisons with male relatives.
• Reference samples come from the victim's personal items (toothbrush, comb) or from biological relatives (parents, children).

Secondary identifiers support but cannot alone establish identity: visual recognition (unreliable when faces are swollen or decomposed, and relatives may be distressed), clothing and jewelry, documents carried, tattoos, surgical implants with serial numbers, and medical findings such as healed fractures or prostheses.

Disaster victim identification follows the INTERPOL protocol:

1. Scene recovery.
2. Post-mortem data collection.
3. Ante-mortem data collection from families.
4. Reconciliation, in which a board confirms matches using at least one primary identifier.

The Philippines has used this process after typhoons, shipwrecks and aviation accidents.

Skeletal remains

The first questions are whether the material is bone, and whether it is human, using gross anatomy, histology (osteon pattern) or a precipitin test. Then the biological profile is built:

Sex

The pelvis alone gives the most reliable estimate, about 95%. The skull alone gives about 90%, and pelvis plus skull together about 98% in adults. Sex cannot be estimated reliably from the skeleton before puberty, so DNA is used instead.

Age

• Children and adolescents: dental development (deciduous teeth erupt from about 6 months to 2 years; the first permanent molar at about 6 years; third molars from about 17 to 25 years), appearance of ossification centers, and fusion of epiphyses (for example, the iliac crest and medial clavicle fuse late, in the early to mid-twenties).
• Adults: changes in the pubic symphysis face, the auricular surface of the ilium and the sternal rib ends, plus closure of cranial sutures. Accuracy falls with age, so adult estimates are given as ranges.

Stature. Living height is estimated from the length of long bones, the femur being best, using population-specific regression formulas such as those of Trotter and Gleser. When only fragments are present, a broad range is reported.

Ancestry, individualizing features and time since death. Healed fractures, surgical plates, dental work and bone disease provide individualizing marks. Weathering, adherent soft tissue, odor and insect remains help estimate time since death, which is highly variable in tropical climates.

Practical rules for the examiner

• Never release a body on visual recognition alone when the face is disfigured or decomposed, or in a mass disaster.
• Photograph and chart everything, and keep samples for DNA before embalming or burial.
• State conclusions with appropriate certainty: "positive identification", "probable", "possible" or "excluded".