Identification

Medicolegal Identification

Definition

The application of Forensic Science and Technology to personalize someone through specific criteria that individualizes them from others throughout their life. This can be used in living persons, deceased persons, or even parts of a dead body or collections of bones.

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Identification of Living Persons

Civil Cases

1. Unconscious person admitted to hospital
2. Amnesia (memory loss)
3. Persons without authentic records when facing legal situations (e.g., marriage)
4. Inheritance matters
5. Military service eligibility
6. Emigration at exit ports

Criminal Cases

1. Criminals who impersonate others
2. Offenders below age of 18 having no official records of age to be tried in juvenile courts (typically ages 12-18 years)

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Main Points of Identification

1. General Features

• Sex, race, age
• Facial features: Color of skin, type and color of hair, color of eyes, moustache, etc.
• Height and weight

2. Clothing (Police Responsibility)

• Check pockets for identity papers
• Note distinctive clothing items

3. Characteristic Marks

• Moles and scars
• Tattoo marks
• Congenital abnormalities or deformities

4. Biometrics

Physical Traits

Related to the shape of the body:

• Fingerprint patterns
• DNA profiles
• Footprints
• Iris prints

Behavioral Traits

Related to personal behaviors:

• Gait patterns
• Voice and accent
• Language patterns
• Handwriting characteristics

5. Photograph

• Profile view and face view are required
• Should capture distinctive facial features

6. Anthropometry

Measurement of different parts of the human body, added to previous steps in criminal cases for comprehensive identification.

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Age Determination

Age has to be determined in:

1. Fetus (prenatal development)
2. Children (postnatal development)
3. Adults (mature individuals)
4. Dead persons (immediate post-mortem)
5. Decomposed or mutilated bodies
6. Skeletal remains (advanced decomposition)

Prenatal Age Determination

Developmental Periods

• Ovum (zygote): 0 to 14 days
• Embryo: 14 days to 8 weeks
• Fetus: 8 weeks to birth (28 weeks)
• Perinatal period: 28 weeks of gestation to 7 days after birth

Postnatal Periods

• Newborn (neonatal): First 4 weeks after birth
• Infant: Up to one year
• Toddler: 1 to 3 years

Fetal Age Assessment Methods

1. Length measurements

   • Crown-heel length
   • Crown-rump length

2. Calculation methods

   • Up to 5th month: Square root of length of fetus = age in lunar months
     • Example: If fetus length is 16 cm, √16 = 4 months
   • After 5th month: Length divided by 5 = age in lunar months

Head Circumference Development

Age	Head Circumference
Birth	35 cm
3 months	40 cm (+5)
1 year	45 cm (+5)
2 years	48 cm (+3)
7 years	50 cm (+2)
10 years	52 cm (+2)

Dental Development for Age Determination

Temporary (Primary) Teeth Eruption

Teeth	Eruption Period
Medial incisor (lower)	6-8 months
Medial incisor (upper)	7-9 months
Lateral incisor (lower)	10-12 months
Lateral incisor (upper)	7-9 months
First molar	12-14 months
Canine	17-18 months
Second molar	20-30 months

Permanent Teeth

Total: 32 teeth consisting of:

• 8 incisors
• 4 canines
• 8 premolars
• 12 molars

Permanent Teeth Eruption Schedule

Tooth Type	Eruption Age
First molar	6-7 years
Medial incisor	7-8 years
Lateral incisor	8-9 years
First premolar	9-10 years
Second premolar	10-11 years
Canine	11-12 years
Second molar	12-14 years
Third molar (wisdom teeth)	17-25 years

Comprehensive Age Determination Table

Age	Skeletal Development (Ossification)	Medicolegal Significance & Identification
6 years	Pubic ramus of ischial bone unites with ischial ramus of pubic bone ID: Central incisors eruption	Age of education begins.
7 years	ID: Central incisors eruption	Age of discrimination (التمييز): - Crimes <7: Guardian responsible - Crimes >7: Child Court (no punishment till 12)
12 years	ID: Eruption of 2nd molar	Child training for work illegal. Partially responsible (punished but not imprisoned till 15).
14 years	*Trochlea unites with capitulum *(humerus)	Cannot commit the crime of rape
15 years	- Trochlea & capitulum unite with shaft of humerus - Ilium, ischium, pubis unite in acetabulum (Y-suture disappears)	End of mother’s custody (الحضانة). Sentenced as adults (reduced sanctions).
16 years	- Lateral epicondyle with humerus shaft - Upper ulna with shaft - Lesser trochanter with femur shaft Male ID: Lateral epicondyle union Female ID: Metacarpals union	Identity cards issued.
17 years	- Medial epicondyle with humerus shaft - Upper radius with shaft - Greater trochanter with shaft
18 years	- Distal metacarpals/proximal phalanges with shafts - Lower tibia/fibula with shafts	Full criminal responsibility begins. Age of majority (21y in some jurisdictions)
20-21 years	Lower ends of radius and ulna with shafts
21 years	- Lower femur with shaft - Upper tibia/fibula with shafts - Ischial tuberosity with ischium
23 years	- Iliac crest with ileum - Sternal end of clavicle with shaft - Basiocciput with basisphenoid
30 years	Closure of sagittal suture (inner aspect)
40 years	- Xiphoid with sternum body - Closure of coronal suture
50 years	- Greater cornu of hyoid with body - Closure of lambdoid suture
60 years	Manubrium sterni with body of sternum
70 years	Closure of all skull sutures except temporoparietal

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Detailed Ossification Centers Y

Humerus:

• Head: Appears at 1 year, Fusion at 14-16 years (female), 14-18 years (male)
• Greater tubercle: Appears at 7 months, Fusion (with head) 2-4 years
• Lesser tubercle: Appears at 7 months, Fusion (with greater tubercle) 5-7 years
• Trochlea: Appears 7-10 years (female), 9-11 years (male), Fusion 9-13 years (female), 11-15 years (male)

Radius:

• Head: Appears at 6 years (female), 8 years (male), Fusion at 14 years (female), 16 years (male)
• Distal end: Appears at 1 year, Fusion at 16.5 years (female), 18 years (male)

Ulna:

• Olecranon: Appears 9-12 years (female), 11-13 years (male), Fusion at 15 years (female), 17 years (male)
• Distal end: Appears 8-10 years (female), 10-11 years (male), Fusion at 17 years (female), 18 years (male)

Femur:

• Head: Appears at 1 year, Fusion at 14-15 years (female), 16-17 years (male)
• Greater trochanter: Appears at 3 years, Fusion at 14 years (female), 17 years (male)
• Lesser trochanter: Appears at 1 year, Fusion at 15-17 years (both sexes)
• Distal end: Appears before birth, Fusion at 14-17 years (both sexes)

Tibia:

• Proximal end: Appears shortly before birth, Fusion at 14-15 years (female), 16-17 years (male)
• Distal end: Appears at 1 year, Fusion at 14.1-14.4 years (female), 16 years (male)

Fibula:

• Proximal end: Appears at 2 years (female), 4 years (male), Fusion at 14-16 years (both sexes)
• Distal end: Appears at 1 year, Fusion at 13-15 years (female), 14-16 years (male)

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Forensic Identification Techniques

Categories of Forensic Science

Biological Forensics

1. DNA Evidence

2. Forensic Entomology

   • Study of insects on decomposing remains
   • Helps determine time since death (post-mortem interval)

3. Forensic Serology

   • Analysis of blood and bodily fluids
   • Blood typing and protein markers

4. Forensic Odontology

   • Dental identification and bite mark analysis
   • Useful for identifying decomposed remains

Forensic Pathology. • Forensic Psychiatry. • Forensic Toxicology. • Bloodstain Pattern Analysis. • Forensic Photography

Physical Forensics

Principles of fingerprint identification (Dactylography) The skin in the palmar aspect of the hand is covered with ridges on which sweat pores open. These ridges are with several types and patterns, which were found to be unique in each individual (l in 64 billion chances for 2 prints to be identical

Forensic anthropology

1. Forensic Art
   • Composite sketching from witness descriptions
   • Image modification and enhancement
   • Age progression for missing persons
   • Post-mortem reconstruction
   • Demonstrative evidence for court presentations

Molecular Forensics

Use of identifying characteristics of molecules in our cells to aid legal investigations -

Compare the DNA and/or blood type of crime scene evidence to that of suspects, or use this information to identify a victim.

Fingerprint Identification – The ridges that run through both the dermis and epidermis create a pattern that remains unchanged throughout a person’s life.

• Reversible atrophy of these ridges can occur in certain diseases such as dermatitis.
• Permanent impairment results from conditions like leprosy or after exposure to radiation.
• Attempts to mutilate fingerprints are sometimes made; however, if only the epidermis is destroyed, the ridge DNA remains intact.

DNA Profiling – The following elements are central to its medico‑legal importance:

• DNA
• Gene
• Locus
• Chromosomes
• Mitochondrial DNA