Identification in Forensic Medicine and Toxicology (FMT)

For 3rd Year MBBS Students

Source: The Essentials of Forensic Medicine and Toxicology, 36th Edition (2026) - Parikh's Textbook of Medical Jurisprudence, Forensic Medicine and Toxicology

What is Identification?

• Unknown dead bodies (mutilated, decomposed, skeletal)
• Disasters (mass casualty, aircraft accidents)
• Criminal investigations (suspect identification)
• Disputed identity (impersonation, insurance fraud)
• Missing persons

Methods of Identification

1. ANTHROPOMETRY (Bertillon System)

1. Body appearance - color of hair, eyes, complexion, shape of nose, ears, chin
2. Body marks - moles, scars, tattoo marks
3. Body measurements:
   • Height, anteroposterior diameter of head and trunk
   • Span of outstretched arms
   • Length of left middle finger, left little finger, left forearm, left foot
   • Length and breadth of right ear, color of left iris
   • Front view photograph + profile view of right side of head

Limitation: Photographs alone are not always reliable as a sole means of identification.

2. DACTYLOGRAPHY (Fingerprint System)

• First used in India in 1858 by Sir William Herschel (West Bengal)
• Systematized by Sir Francis Galton in 1892
• First Fingerprint Bureau established in Kolkata

Loop fingerprint - showing Core and Delta landmarks

• Final identification is by comparison of ridge characteristics, not patterns alone
• Ridge characteristics: ridge endings, bifurcations, lake formations, island formations
• Minimum 8 points of comparison for positive identification (Supreme Court ruling)
• Fingerprint patterns are NOT inherited - paternity cannot be proved through them
• Pattern is different even in identical twins
• Patterns are permanent and distinctive throughout life

3. POROSCOPY

• Ridges are studded with microscopic pores (mouths of sweat gland ducts)
• Each mm of ridge contains 9-18 pores; thousands per cm²
• Pores are permanent, vary in size, shape, width
• Useful when fingerprint is too smudged for ridge detail comparison

4. FOOTPRINTS AND FOOTMARKS

• The walking gait pattern (stride) can be individualized
• Step length: adult woman = 45-55 cm; adult male = 63-70 cm
• Footmarks are recorded by photography, casts, or lifting
• Prints in yielding soil indicate shoe size, approximate weight, and peculiarity of gait
• Imprint on hard surface is smaller than actual foot; on mud/clay is larger

5. PALATOPRINTS

• Rugae (ridges) in the anterior hard palate are individual-specific and permanent
• Categorized (Lysell) as: Primary rugae (>5 mm), Secondary rugae (3-5 mm), Fragmented rugae (2-3 mm)
• Used similarly to fingerprints

6. LIP PRINTS (Cheiloscopy)

• Fissures and grooves of lips are characteristic of the individual
• 6 patterns described by SUZUKI - vertical, branched, intersected, reticular, etc.
• 24 characteristic details identified; identification established if 7-9 characteristics tally
• Found on crockery, cloth, paper, windowpanes, cigarette ends

7. EAR PRINTS

• Four basic ear shapes: oval, round, rectangular, triangular
• Three prints taken from suspect: functional pressure, gentle pressure, more pressure on glass
• Most ear prints found on doors or windows
• Made visible and photographed like fingerprints

8. SKULL-PHOTO SUPERIMPOSITION

• Technique applied by Glaister and Brash (1935) in the famous Ruxton case
• Used to determine whether a skull belongs to a person in a photograph
• The photo is enlarged to natural size; skull is mounted and aligned with the face outline
• Points compared: eyes within orbital plates, nasal bones, chin, zygomatic arch, etc.
• Useful when only skeletal remains are available

9. OCULAR (EYE) BIOMETRICS

• Retinal blood vessel pattern is unique to each individual
• ~70 times more accurate than iris scan
• Nearly impossible to fake
• Limitation: retina decays quickly after death; altered in cataract, glaucoma, retinal degeneration, diabetes

• Iris is structurally unique despite genetic contribution to coloration
• Iris is located using landmark features; distinct shape allows feature isolation
• Does not decay after death as quickly as retina

10. DNA FINGERPRINTING (Most Definitive Modern Method)

• The most scientifically reliable method of identification
• Can identify from blood, semen, hair roots, saliva, bone
• Useful in mass disasters, paternity disputes, criminal investigations
• Unlike conventional fingerprints, DNA patterns ARE inherited and can prove paternity
• Different from dermatoglyphic fingerprints (which cannot prove paternity)

11. DENTAL IDENTIFICATION

• Dental records, X-rays, and unique tooth patterns are used
• Requires antemortem dental records for comparison
• Highly resistant to fire and decomposition
• No central dental database exists (unlike fingerprint or DNA databases)
• Used extensively in mass disaster victim identification

Summary Table for Quick Revision

High-Yield Exam Points

1. Most reliable method of identification = DNA fingerprinting (or fingerprints for classical forensics)
2. First fingerprint bureau = Kolkata; First used in India = Sir William Herschel (1858)
3. Fingerprint ridge pattern appears at 12-16 weeks of intrauterine life
4. Loop patterns are most common (60-70%)
5. Minimum 8 points of comparison for positive fingerprint identification (Supreme Court)
6. Fingerprints are different even in identical twins
7. Paternity CANNOT be proved from fingerprint patterns (patterns not inherited)
8. Poroscopy = study of sweat pores on ridges (described by Locard)
9. Skull-photo superimposition - first used in Ruxton case by Glaister & Brash
10. Step length: male = 63-70 cm; female = 45-55 cm

• The Essentials of Forensic Medicine and Toxicology, 36th Edition (2026), pp. 94-99
• Parikh's Textbook of Medical Jurisprudence, Forensic Medicine and Toxicology