Anthropometry

• Anthropometry: The first scientific method of criminal identification

  • Attributable to Alphonse Bertillon (1853–1914)

  • Bertillonage as a scientific method of personal identification was ultimately supplanted by the fingerprinting system.

• Descriptive data: Color of hair, eyes, complexion, shape of nose, ears and chin.

• Body measurement: Height, AP diameter of head and trunk, span of outstretched arms, length of middle finger, left little finger, left forearm and left foot, length and breadth of right ear, and color of left iris (11 such measurements).

• Body marks: Moles, scars and tattoo marks.

• Photographs: Front view and right profile of the head are also taken

Dactylography

• Dactylography: The study of fingerprints as a method of identification

  • In 1858, Sir William Herschel was the first to use this system.

  • In 1892, Sir Francis Galton formalized this approach.

• Fingerprints

  • Friction ridge skin covers human and other ape fingers, palms, and soles.

  • Dermal carvings or ridges emerge in the 12th–16th week of IUL and finish by the 24th week.

  • No two hands have the same patterns.

  • Genetics determine the fundamental forms of patterns and ridges, however identical twins have identical genetics but distinct fingerprints.

  • Until dermal skin injury occurs, fingerprints do not alter.

  • When stung by a bee, fingerprints temporarily disappear but reappear after the swelling goes down.

  • Criminals may remove fingerprints permanently to avoid prosecution. Burns, acids, and plastic surgery erase.

  • Leprosy, radiation, and electric harm permanently damage fingerprint patterns.

• Fingerprint Patterns

  • Loop Pattern: A loop is formed when one or more ridges entering from the same side recurving, existing from the same side.

    • Radial loop: The loop where the ridges start from the radial bone or thumb side of the hand and recurving around the core and exiting to the same side of the hand.

    • Ulnar loop: The loop where the ridges start from ulnar loop or little finger of the hand and recurving around the core and exiting to the same side of the hand.

  • Arch Pattern: the ridges run from one side of the print to another side, forming an arch like formation.

    • Plain arch (A): The ridges run from left side to other side with a small rise at the center like a hill or hump.

    • Tented arch (T): In this ridges entering from left side making an upright thrust at the center flowing towards the right side of the pattern.

  • Whorl Pattern: Almost 30-35 % of populations have whorl pattern. Whorl is having one core and 2 deltas.

  • Composite Pattern: the composites are combinations of all the above-mentioned patterns.

    • Central pocket loop: a combination of a loop and a whorl.

    • Lateral pocket loop: a double loop pattern in which two loops are formed either by overlapping or surrounding one another and both the loops after terminating exiting from the same side of the delta.

Types of Evidentiary Fingerprints

• Patent (visible) print: Needs no processing to be clearly recognizable as a fingerprint. It is often.

  • Grease, dark oil, dirt, and blood fingerprints can be seen and compared without processing.

• Plastic (impression/indentation) print: A recognizable fingerprint indentation in a soft surface, such as butter, soap, cheese, paint, putty or tar.

  • Such prints have a distinct three-dimensional character, immediately recognizable, and require no further processing.

• Latent print: It requires additional processing to be rendered visible and suitable for comparison.

  • Latent prints are developed, enhanced, or visualised to make them visible and comparable.

Development/Enhancement of Latent prints

• Locard’s Principle of Exchange: ‘When two objects come into contact with each other, there is always some transfer of material from one to the other’; hence, the great importance of visualizing them onto useful evidence.

• Composition of latent print residue: Palmer and planter surfaces are hairless and sebaceous gland-free, but sweat glands are abundant, producing latent fingerprint residue.

  • Sebaceous discharges from touching the face are also prevalent.

  • Perspiration contains mostly amino acids, urea, and lactic acid and mostly sodium and potassium chlorides.

  • Fingerprints are stable chemicals that may last forever unless subjected to excessive heat, humidity, or friction.

Fingerprint Development

• For non-porous surfaces

  • Visual examination: Oblique illumination may reveal latent fingerprints, particularly if the surface is smooth and clean.

  • Fluorescence examination: High intensity light source or argon-ion laser or UV light may reveal latent fingerprints.

• Development techniques (Non-Porous Surfaces)

  • Vacuum metal deposition (VMD): Most sensitive, being capable of detecting monolayer of fat by sequential deposition of a thin coating of thermally evaporated gold followed by zinc.

    • It can leave fingerprints on waterlogged surfaces.

  • Fingerprint powders: One of the oldest techniques for detecting fresh latent prints. It is widely used, but insensitive.

  • Superglue fuming: Can be used on any nonporous surfaces, and is particularly useful on surfaces such as rough or grained plastic surfaces which cannot be easily treated using VMD.

    • It is composed of methyl or ethyl cyanoacrylate which polymerize with latent prints.

  • Small particle reagent (SPR): Consists of a suspension of molybdenum disulfide suspended in aqueous detergent solution, which is applied by spraying or immersion.

  • Iodine fuming: One of the oldest and cheapest methods, and can develop recent prints on porous and non-porous surfaces

• For porous surfaces

  • Visual examination is less likely to reveal fingerprints on porous surfaces.

  • Fluorescence examination may sometimes detect fingerprints either by the fluorescence of naturally occurring components or fluorescence of some contaminants.

• Development techniques (Porous Surfaces)

  • DFO (1,8-diaza-9-fluorenone): It is the most sensitive reagent available for detecting fingerprint on porous surfaces.

  • Ninhydrin: It is a widely used chemical which reacts with amino acids and produces a deep blue or purple color known as Ruhemann’s purple.

  • Powders: Smooth papers may be treated with black or magnetic powder, although these will usually detect recent fingerprints.

  • Superglue fuming: may be used on some smooth surfaces such as cigarette packets.

  • Physical developer: It is the only available technique for detecting fingerprints on a wet porous surface.

• Other Methods

  • Radioactive sulfur dioxide: Useful for fabrics and adhesive tapes.

  • Sudan black: Useful for surfaces contaminated by grease or foodstuffs.

  • Osmium tetraoxide: Useful for both porous and non-porous surfaces.

  • Electronography: This technique involved dusting the skin surface with lead (or iron) and then exposure to long wave X-rays (Grenz rays).

  • Scanning electron microscopy with an energy dispersive X-ray spectrometer can be used for imaging of latent fingerprints.

    • However, it is of little use for casework because its application often requires a small area to be cut from the exhibit and coated with a conductive material to prevent the sample charging.

Fingerprint Classification

• The US modified Henry system classifies 10-print sets or fingerprint cards for one person.

• Computerized fingerprint storage and retrieval systems make searching larger files for single and partial prints easy. It has also rendered classification largely unnecessary.

• For decades, a "minimum number of minutiae (points)" rule was followed. In practise, 12 fine comparisons proved identity.

• Resolution in 1973 discouraged 'static threshold' identification ideology.

  • The "floating threshold" eliminated the need for a minimum number of features for fingerprint identification.

• Experts use three levels of detailed evaluation of the friction ridge formations to come to a conclusion.

  • Level 1: The ridge flow (pattern type, ridge count and focal areas such as delta, core and orientation).

    • Individualization or matching the print cannot occur at this level.

  • Level 2: The ridge path (Galton details or ‘points’) includes ridge endings, bifurcations, dots, combinations of the above and their relationship to one another.

    • Individualization can occur at this level.

  • Level 3: Poroscopy and edgeoscopy both involve detail and are used in latent prints by examiners even without their conscious knowledge.

Medico-legal Application

• Identification of criminals with scene fingerprints

• Identification of fugitive through fingerprint comparison.

• Criminal identifying information exchange with foreign identification bureaux in mutual interest.

• Identification of unknown deceased person, persons suffering from amnesia, missing persons and unconscious patient.

• Identification in disaster work.

• Identification in case of accidental exchange of newborn infants.

• Identification of licensing procedure for automobile, firearm, aircrafts, etc.

• Bank forgeries and identity theft.

• Electronic fingerprint readers are used for security applications like computer user log-in authentication.

• Ridgeology: refers to friction ridge identification that is associated with all the ridges on the volar areas and not just on the fingertips.

• The first ‘Fingerprint Bureau’ in the world was officially established in Kolkata on 12th June 1897 at Writers’ Building

• Automated Fingerprint Identification System (AFIS): A storage, search, retrieval and exchange system for finger and palm print electronic images and demographic data

Poroscopy

• Poroscopy: A specialized study of pore structure found on the papillary ridges of the fingers as a means of identification.

• Micropores from subepidermal sweat gland duct mouths cover fingers and hands.

  • Each millimeter of ridge contains 9–18 pores.

  • Finger ridges have 550–950 sweat pores per square centimetre and palms and soles 400.

• In 1912, Edmond Locard invented poroscopy to study fingerprints.

  • He found that pores, like ridge features, are permanent, unchangeable, and unique, making them valuable for identifying people when ridges are few.

• Edgeoscopy: Coined by Salil K Chatterjee in 1962; the examination of papillary ridge edges to identify them.

• Footprints: Skin patterns of toes and heels are as distinct and permanent as those of fingers.

  • Footprints of newborn infants are used in maternity hospitals to prevent exchange or substitution of infants.

  • Records are also kept for air force flying personnel.

• Forensic podiatry: Specialty using clinical podiatric knowledge for the purpose of person identification.

Cheiloscopy

• Cheiloscopy: The study of lips.

• Lip prints appear when a person's lips touch an item at the crime scene.

• Suzuki has divided lip prints into five main types.

  • Type I: represents grooves running vertically over the lips.

  • Type II: represents the branched grooves.

  • Type III: represents the intersected grooves.

  • Type IV: represents the reticular pattern, much like a wire mesh.

  • Type V: represents all other patterns. These are irregular non-classified patterns.

Enhancement and Utilization of Lip prints

• Fingerprint powders and foil are the simplest technique for this.

• Aquaprint and cyanoacrylamide work too.

• The trace usually shows the central 10 mm of the bottom lip, which is used for categorization.

• It is useful for personal identification.

• Lip prints are seldom used in criminal cases since our courts have not proved their veracity.

Trichology

• Trichology: Examination of hair.

• Hair can be found on decomposing bodies or on the weapon of offence after a crime.

• Hair consists of:

  • Root: The portion of hair at the base of skin. It has a base known as bulb, embedded inside the hair follicle.

  • Shaft: The portion of hair lying above the skin and tapers to terminate at the free end as tip.

• Three Zones of Hair

  • Cuticle: Outermost layer, consists of thin nonpigmented microscopic scales.

  • Cortex: Middle layer, consists of longitudinally arranged elongated cells.

    • Within these cells are fibrils on which there may be granules of pigment.

    • It has keratin that is responsible for the charring and acrid odor when the hair is burned.

  • Medulla: Innermost layer, composed of keratinized remains of cells.

• Two groups of Fibers

  • Natural fibers: These are subdivided into 3 classes: animal (e.g. silk, wool and hair), vegetable (e.g. cotton, jute and coir) and mineral (e.g. asbestos).

  • Artificial fibers: These are subdivided into syntheticpolymer, natural-polymer and other fibers.

  • All animal fibers except silk can be considered as hair fibers.

  • Most natural fibers have distinctive appearances that can be detected under the comparison microscope.

  • Synthetic fiber that cannot easily be identified with the microscope can be subjected to infrared spectrophotometry.

• Medullary index (MI): The ratio of the diameter of the medulla to the diameter of the cortex.

• Hair Origination:

  • Scalp hair: Long, soft, taper from root to tip, split ends, and circular on cross section.

  • Beard and moustache: Thicker, straight, blunted tip, and triangular on cross section.

  • Axillary and pubic hair: Stout, short, lack of uniformity, and curly with frayed or split ends.

  • Eyebrow, eyelashes and nostril hair: Short and stiff, thick, tapering abruptly, and triangular on cross section.

  • Body hair: Soft, fine and flexible, lack of uniformity of medulla, milder pigmentation, and narrow tip.

• Hairs from Ages:

  • Lanugo hair: Hair of the newborn are fine, downy, soft, non-pigmented, non-medullated, and cuticular scales have smooth edges.

  • Adult hair: These are coarser, pigmented and medullated having a complex cuticular pattern.

  • Gray hair: These are apparent after the age of 40, and are devoid of any pigment.

• Alteration of Hair:

  • Bleached or colored hair are dry, brittle, lusterless and rough.

  • Color in cuticle indicates dyeing.

  • Curly appearance accompanied by constrictions in the shaft is indicative of permanent waving.

  • Hair color is lighter in diseases, such as kwashiorkor, malnutrition and certain vitamin deficiencies.

  • Tunneling of hair by fungal hypae can produce distinctive transverse lines—seen in hair exposed to fungi, and occur in buried bodies.

Superimposition

• Superimposition: Technique applied to determine whether the recovered skull is that of the person in the photograph.

• Skull-photo superimposition involves three phases: photography, video, and computer-assisted.

• Comparison image: It is enlarged to the size of the unknown skull and positioned in the same orientation as the face shot during photographic superimposition.

• Computer-assisted superimposition: Which digitizes the skull and face photos using a video computer and suitable software, compares the two images morphologically by image processing.

• The whole skull is needed for identification.

  • Despite a fair skull-superimposition match, it cannot be definitively recognized as the putative individual without the mandible.

• If the skull and face image show incisors and canines, definitive identification may be possible.

• The outline, facial tissue thickness at various anthropometric points, and positional relationships between skull and face—eyebrow to supraorbital margin, eye to orbit, nose to nasal aperture, lips to teeth, and ear to external auditory meatus—should be considered when assessing anatomical consistency.

• The skull might be the pictured person's if they match.

• The test is negative since the skull and photos are not the same individual.

Forensic Odontology

• Forensic Odontology: It deals with the application of dentistry to aid in the administration of justice.

• The work of a forensic odontologist includes:

  • Dental data used to identify unidentified remains.

  • Bite marks on the assault victims may be recognized.

  • Bite marks and a suspect's teeth are compared, and an expert witness presents this information in court.

  • Recognizing biting marks on various materials, like wood, leather, and food.

  • Estimating the age of the skeletal remains.

Bite Marks

• Bites are commonly seen in cases of:

  • Sexual assault: Marks are usually seen on breasts, neck, shoulders, thighs, abdomen, pubis or vulva.

  • Child abuse: Marks are seen anywhere on the body, such as arms, hands, shoulders, cheeks, buttocks and trunk.

  • Bite marks on foodstuffs (apples, cheese or chocolate), leather (key rings or belts) and wood (pencils) in cases where a perpetrator might have taken a bite out of something in the victim’s home and left it behind.

  • Police officers may be bitten by the resisting offenders.

  • In sporting events, like football, rugby or wrestling.

  • In assaults, where marks may be found anywhere on the body.

• Nature of bite marks: Comprise of a crop of punctate haemorrhages varying from small petechiae to large ecchymoses merging into a confluent central bruise.

• Human bite: It is semicircular or crescentic owing to the front teeth (incisors and canines) with a gap on each side due to upper and lower jaw separation, whereas an animal bite is deep parabolic arch or U-shaped.

  • Self-inflicted bite marks: These are present on accessible parts of the body, e.g. shoulders or arms, usually seen in psychiatric patients or teenage girls.

  • Accidental marks: These are resulting from falls on to the face and during fits, biting of tongue and lips may also be there.

  • In sexual assault, sucking action during bites reduces the air pressure in the centre and produces multiple petechial haemorrhages due to rupture of small capillaries and venules

Bite mark investigation

• Photograph: Bite mark is photographed from different angles.

• Swabbing of saliva: To identify or exclude assailant from ‘secretor’ status who exude blood group substances in the saliva.

• Impression of bite mark: Plastic substance (rubber or silicone based) or plaster of Paris is laid over the bite mark that hardens and produces a permanent negative cast of the lesion.

• Skin carrying the bite is removed and preserved in formalin during autopsy.

Dental Profiling

• Dental profiling: A forensic dentist's "picture" of a person's general features when dental records are unavailable and other methods of identification are not possible.

  • It usually includes the deceased's age, ancestry, sex, and socioeconomic status.

  • It is sometimes possible to provide additional information on occupation, dietary habits, habitual behaviours, and dental or systemic diseases.

• DNA analysis and microscopic examination of teeth for Y-chromatin can determine sex.

• Teeth are good sources of DNA because they can withstand incineration, immersion, trauma, mutilation, and decomposition.

  • This biological material can prove identity when dental identification fails.

Charting of Teeth

• On the charts following peculiarities are recorded:

  • Any extractions, recent or old.

  • Any fillings, number, position and composition.

  • Artificial teeth, whether of gold, porcelain or stainless steel.

  • Prosthetic work in mouth, such as bridge work or braces.

  • Any crowned teeth.

  • Any broken teeth.

  • Pathological conditions in teeth, jaws or gums.

  • Congenital defects, such as Hutchinson’s teeth or ectopic teeth.

  • Malpositioned teeth that are rotated or tilted.

  • General state of hygiene, like caries, plaque, tobacco staining, or gingivitis.

  • Racial pointers, such as shovel shaped upper central incisors, enamel pearls, Carabelli’s cusps or multi-cusped molars

• Most widely used systems are:

  • Universal (Cunningham) system: Follows the plan advocated by American and International Society of Forensic Odontology.

    • The permanent teeth are numbered from 1 to 32, and lettering the deciduous teeth A to T, starting at the posterior upper right and continuing in a clockwise direction.

  • Palmer’s notation: Adult teeth are numbered 1 to 8, with deciduous teeth indicated by a letter A to E.

    • The Palmer notation consists of a symbol (┘└ ┐┌) designating in which quadrant the tooth is found and a number indicating the position from the midline.

  • Haderup system: It is similar to Palmer notation, except it uses a plus sign (+) to designate upper teeth and a minus sign (-) for lower.

    • For the deciduous teeth, a zero was additionally placed in front of the number.

  • FDI (Federation Dentaire Internationale)-two-digit system: A two-digit notation capable of indicating tooth and quadrant was developed.

    • Thus, lower right canine will be numbered 43.

    • This was adopted as the International Standard.

  • Modified FDI system: In this method, the tooth and quadrant are designated by a separate number.

    • Right quadrant was designated by 2 and 3, and left was designated by 1 and 4 in permanent teeth.

  • Diagrammatic or anatomical chart: In this, each tooth is represented by a pictorial symbol that gives the same number of tooth surfaces as those on that particular tooth in mouth.

    • Incisors and canines are represented by four surfaces, premolars and molars by five.

Miscellaneous Methods of Identification

• Clothes and Personal Effects

  • They aid identity in mass disasters.

  • For identification, clothing, driving license, mobile phone, watch, glasses, jewellery, and wallet discovered on a deceased corpse must be preserved.

  • Tailor marks, foreign material, and tears are checked.

• Occupational Marks

  • These help identify unknown dead bodies because certain occupations leave marks, such as clerks' callosity on the proximal part of the right middle finger where the pen rests or dyers/photographers' stained fingers.

• Handwriting

  • Doctors rarely testify about handwriting, but experts do.

  • The doctor may evaluate someone who claims paralysis or mental impairment to see whether they can write.

• Speech, Voice, Ticks, Manner and Habit

  • Stuttering, nasal twang, and jerky facial or shoulder movements can sometimes identify a living person.

• Other methods of identification

  • Palatoscopy/palato-print/rugoscopy: It is the study of palatal rugae in order to establish identity.

  • Fronal sinus print: It is unique to a particular individual, and these are permanent and fixed and rarely alter following infection or injury.

  • Vascular grooves and sutural pattern: The sutural pattern on the skull bone particularly of sagittal and lambdoid sutures are complex and are individualistic.

  • Ear print: It is the study of shapes of the ear lobules and tips of ears as well as the hardness or softness of the helix and lobules, and hairiness of the helix and tragus.

  • Nose print: The lines on the nose and shape of the tip of nose are considered to be individualistic

  • Nail print: It is the study of the depressions and elevations (striations), numbers, distribution and dimensions of the ridges on the surface of the nails which are considered to be individualistic.

  • EV method of identification: The electrocardiogram (ECG or EKG) and vector cardiogram (VCG) trace expresses cardiac features that are unique to an individual.

  • ‘Barium meal’ X-ray of stomach: It is also considered to be individualistic and may be helpful in identification, if previous record is available.