Dactylography is the study of fingerprints in human

Dactylography, also known as fingerprinting, is a method of identifying individuals based on the unique patterns of ridges and valleys on their fingers. These patterns are formed during fetal development and remain unchanged throughout a person's life. Dactylography is used in various applications, including:
* Law enforcement: Fingerprints are collected from crime scenes and compared to known fingerprints in databases to identify suspects.
* Immigration: Fingerprints are used to verify the identity of individuals entering or leaving a country.
* Personal identification: Fingerprints can be used as a form of personal identification, such as on driver's licenses or passports.
There are several different types of fingerprint patterns, including:
* Loops: These patterns have one or two ridges that enter and exit from the same side of the finger.
* Whorls: These patterns have a central ridge that forms a circle or spiral.
* Arches: These patterns have ridges that run parallel to each other.
Dactylography is a highly accurate method of identification, and it is used in many different fields.
Fingerprint refers to the unique patterns of ridges and valleys found on the fingertips and other parts of the hands. These patterns are formed during fetal development and remain unchanged throughout a person's life, making them a reliable method of identification.
Key characteristics of fingerprints:
* Uniqueness: No two people have identical fingerprints, even identical twins.
* Permanence: Fingerprints do not change over time, except for minor injuries or scarring.
* Classification: Fingerprints can be classified into different patterns, such as loops, whorls, and arches.
Applications of fingerprints:
* Law enforcement: Fingerprints are used to identify suspects and victims in criminal investigations.
* Personal identification: Fingerprints are used on passports, driver's licenses, and other forms of identification.
* Biometric security: Fingerprint recognition technology is used in smartphones, laptops, and other devices for access control and security.
Dactylography:
The study and analysis of fingerprints is called dactylography. It involves the collection, classification, and comparison of fingerprints for identification purposes.
Would you like to know more about a specific aspect of fingerprints or their applications?
Forensic Science is the application of scientific knowledge and techniques to the investigation of crime. It involves the collection, preservation, identification, and analysis of physical evidence from crime scenes. Forensic scientists work with law enforcement agencies to help solve crimes and bring perpetrators to justice.
Common areas of forensic science include:
* Biology: Analyzing DNA, blood, and other biological evidence.
* Chemistry: Examining substances like drugs, poisons, and explosives.
* Physics: Investigating accidents, ballistics, and fingerprints.

1. DACTYLOGRAPHY SUBMITTED BY: ATUL SAINI SUBMITTED TO: DR. NARINDER KUMAR

2. FINGERPRINTING/ GALTON SYSTEM/ DERMATOGLYPHICS. DEFINITION : Dactylography is the study of fingerprints as a method of identification.. First used by Sir William Herschel in India in 1858. Sir Francis Galton systematized it in 1892. Principle :

Fingerprint patterns are unique (1 in 64 billion chances of being identical)
Remain unchanged throughout life.

Can’t be altered except by destruction of true skin Present from birth both on epidermis and dermis.

3. What are fingerprints ? The fingers, palms of the hands, and soles of the feet of humans bear friction ridge skin. On the tip of fingers, the friction ridge skin forms a number of basic patterns. The arrangement and distribution of the patterns are unique to an individual and no two hands resemble each other. Genetic makeup plays a part in determining the patterns and ridges, but it is not the only factor, as identical twins have distinguishably different fingerprints.

4. TYPES OF FINGERPRINT PATTERNS LOOP (Ulnar/Radial) - 60-70 % WHORL - 30-35 % ARCH - 5-10 % COMPOSITE - 2-3 %

5. DELTA : Convergence of ridges from three directions is called a DELTA ( Triradius ).

6. ARCH :

An arch has friction ridges that enter on one side of the finger and cross to the other side while rising upward in the middle. Types : Plain- the arch is mild. Tented- the arch is spiked upward (stand at an angle of 45 degree or more).

7. Loop : A loop must have one or more ridges entering and exiting from the same side it began. Loops must have one delta (a “Y” pattern from diverging ridges) Types :

Radial — opens toward the radial side (thumb). Ulnar– opens toward the ulnar side (little finger).

8. Whorl : A whorls, ridges make a complete 360 degree circuit around the centre of the print. There are two deltas.

9. COMPOSITE Composite contains at least two different patterns, other than the basic arch. Sometimes, it is also referred to as ‘accidental’.

10. Parts of a Fingerprint:

11. RECORDING OF FINGERPRINTS: Hands washed, cleaned & dried. Recorded on unglazed white paper using printer’s ink. TYPES OF FINGERPRINT IMPRESSIONS:

12. PLAIN IMPRESSION : is obtained by gently pressing the inked surface of the tip of finger on paper. ROLLED IMPRESSION: is taken by rolling the inked finger from side to side. LATENT PRINT: requires additional processing to be rendered visible and suitable for comparison.

13. Fingerprint development 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 fingerprint. DEVELOPMENT TECHNIQUES Fingerprint Powders – milled aluminum or brass Iodine Fuming – fumes of iodine form a brown image when absorbed by fingerprints. Superglue Fuming etc.

14. Advantages : Applicable to persons of all ages. Can be obtained from putrefied bodies.

Absolute identification possible.

Special training or expensive instruments not necessary.

The system lends itself to easy classification.

The print can be transmitted from one place to the other via a coded or digitalised message.

The actual print is always available to check any suspected error

15. Medico legal Importance: Recognition of chance impressions left on crime scene.

Identification of weapon used for committing crime.

Identification of habitual criminals, suicides, deserters, persons) suffering from memory loss, those dead or unconscious after being involved in an accident.

Identification of decomposing or mummified bodies:

Prevention of impersonation. As an extra precaution on cheques, bank notes & legal documents.

16. Record of Fingerprint

17. Permanent Impairment Leprosy.
Electrocution.
Radiation exposure.
Not altered but distance b/t ridges changed:

18. Ridge alteration - Scleroderma.

- Dry or atrophic skin.

- Scar.

19. Preservation If required to preserve whole hand, full fingers or even fingertips, cutting should be done at the proximal joints. The epithelium carefully separated from underlying tissues sparing the print which is then spread on a slide and preserved between two glass slides after being air dried.

20. • Left thumb impression- male.

• Right thumb impression – female.

• Left thumb impression in lieu of signature.

• Criminal cases, impressions of all digits of both hands taken.

In dead body, if fingertips dried & hardened – skin rendered soft by application of oil or Vaseline & prints taken after soaking fingers in an alkaline solution to restore fingertip. • If skin peeled off as a result of putrefaction, burns or drowning, prints can still be recorded either from the dermis or from peeled-off skin hardened by formalin.

• If fingers shrivelled, immerse in 20% acetic acid for 24-48 hours, surface of the fingers can be rounded out by injecting glycerine , hot water into the tissues.

21. AFIS (Automated Fingerprint Identification System): AFIS is a storage, search, retrieval and exchange system for finger and palm print electronic images and demographic data (biometric data). To match a print, a technician scans the print in question, and computer algorithms are utilized to mark all points, cores, and deltas detected on the print. This enables a fingerprint to be compared with millions of file prints within a matter of seconds.

22. Some criminals have actually deformed their fingerprints by surgery, burning or application of acid in an attempt to destroy the papillary ridges. Surgically altered fingerprints by skin grafting

23. THANK YOU