Identification: Definition, Identification of unknown person, dead bodies and remains of aperson by age, sex, stature, dental examination, scars, tattoos, dactylography, DNA typing

By -

Saurabh Bhargava

Identification

• Identification means determination of individuality of a person

• Complete/Total identification– Exact specification of an individual

• Incomplete/Partial identification– Recording of certain information or data which will

ultimately help complete or total identification

Need of Identification

1. In living persons

2. In dead persons

3. In skeletal remains

Data required for identification• Race, religion & nationality• Sex• Age• Stature, general body built• Complexion• Features of hairs• Congenital & acquired peculiarities like malformations, birth marks, moles,

scars, tattoo marks, occupational marks etc• Dress, ornaments and other belongings including pocket/purse, diary,

passport etc• Anthropometric measurements• Fingerprints, lip prints, palate prints etc• DNA records

Race

• However there has been extensive inter-racial admixing over the last thousands of years, still the primary racial types are easily recognized- – Caucasians or Caucasoids– Mongolians or Mongoloids– Negroes or Negroids

Racial differentiationCaucasians Mongolians Negroes

Thin & fair skin Yellowish or pale skin Black & tough skin

Blue or grey iris Black iris Black iris

Thin, straight/wavy, fair/light brown/reddish scalp hair

Moderately thick, Black, straight/wavy hairs

Thick, black, curly/wooly hairs

Raised forehead Inclined forehead Small & compressed forehead

Roundish, mesocephalic skull (CI= 75-80)

Squarish, mesocephalic or brachy-cephalic (CI= 80-85) skull

Narrow, dolico-cephalic/oblong skull (CI= 70-75)

Sex determination

• Question of sex determination arises in following conditions-– Gonadal dysgenesis cases in living persons– True/pseudo hermaphroditism– Mutilated dead bodies– Extremely decomposed dead bodies

Methods sex determination

• Sex of a person can be determined by any one of the following methods-– Physical morphology– Studies of bones– Microscopic study of sex chromatins in cells– Dress (not always reliable)– Gonadal biopsy– Hormonal study (in cases of intersex)– Dental methods

Sexing based on skull bone morphologies

Sexing based on pelvic bones

Sexing based on long bones

Estimation of age

• Age of a person in post-natal life can be determined by following methods-

– Physical or morphological features

– Some laboratory tests (in infants)

– Age estimation by teeth

– Age estimation by ossification activities & growth of bones

Eruption sequences of temporary dentition

Eruption sequences of permanent dentition

Stature • By STATURE we mean body height or body dimension in

vertical direction.

• Stature is an important criterion for identification of a person.

• Starting from the intra-uterine life, stature increases upto early 20’s of that person

• After this age, though not of much significance, it slightly reduces with further increase of age.

Methods of stature estimation

• Karl Pearson’s formulae

• Trotter & Glesser’s formulae

Tattoo marks• Tattoo marks are fairly good identification mark, both for living as

well as dead subjects.• They may provide wide range of informations about the person

possessing them• In connection with identification; tattoo marks may speak about-

– Race– Nationality– religion– Occupation– Language– Name of the person– Name of the relative, friend or lover

Scars for identification

• A scar is a product of healing of a wound by fibrosis and other body mechanisms

• A scar is made of fibrous tissue devoid of hair follicles, pigment & sweat glands and with lesser vascularity

• All scars, in the truest sense of their histological morphology, are permanent, which may change in their size during the growing ages but their shapes remain unchanged all throughout the life.

• This permanency of scar makes it an important tool of identification of a person

Scar conti…

• To record a scar as identification mark, it is to be noted in terms of-– Size– Shape– Site in relation to two anatomical landmarks– Whether raised or depressed in relation to

surrounding tissue– Whether freely movable or fixed with deeper

tissue

Dactylography

• Study of fingerprints as a method of identification is known as DACTYLOGRAPHY or DACTYLOSCOPY or HENRY-GALTON SYSTEM OF IDENTIFICATION.

• It is the process of taking the impressions of papillary ridges of the finger tips, for the purpose of identification of a person.

• Identification by this method is ABSOLUTE, without any chance of error

Basics of Dactylography

• Uniqueness– Ridge pattern in two fingers differs and it can

never be identical in two persons• Permanent – Once formed, the ridge pattern in an individual

never changes except for the size

Types of finger prints & their distribution in population

• Loop – about 65%• Whorl – about 25%• Arch – about 7%• Composite – about 2-3%

Elements of fingerprint- type lines- delta- core

DNA for identification

• Identification by using DNA is also known as DNA fingerprinting in forensic practice

• Using PCR technique, a person can be identified in definite term from his/her old dead body remains, if his/her parents or children are available

Thank you