Fingerprints

By @forensicfield

PRINCIPLES OF FINGERPRINTS

1. A fingerprint is an individual characteristic.

  • No two fingers have the same fingerprint.
  • Identical twins are similar but not identical.

2. Fingerprint remains unchanged during a lifetime.

3. Fingerprint has general ridge patterns that permit them to be classified.

BIOLOGICAL PRINCIPLES

Fingerprints follow three basic biological principles:

PATTERN TYPE: – All fingerprints can be classified into pattern types.

UNIQUENESS:-Each fingerprint is unique, no two people have the same fingerprints.

PERMANENCE: -Fingerprints are unchanging from 3 months fetal life until decomposition.

DEVELOPMENT OF FINGERPRINT

Fingerprint ridges are formed during the third to fourth month of fetal development and their formation completed by the sixth months.

Chance Print

The Fingerprint Left By The Culprit At The Crime Scene Are Better Known As “Chance-prints” And Very Often Found Mainly Of Three Types:

1.) Plastic Prints / Impression

These Occur When A Finger Or Palm Touches Or Presses Against Plastic Material.

These Prints Are Usually Found On Materials Such As Soap, Mud, Pitch, Melted, Wax, Fresh Paint, Putty, Butter, Gum Of Envelop, Grease, Adhesive Tape, Thick Dried Blood, Negative Film, Plastic, Explosive Etc.

Fingerprint Found On These Surfaces Are Of Three Dimensional Natures.

2.) Patent Fingerprints / Visible 

These are prints that are created from the finger contaminated with foreign materials such as blood, paint, grease, ink, oil, dust, mud, soot, dry flour, and face-powder.

3.)  Latent Prints / Invisible

Latent or invisible fingerprints are the most often found at the crime scene on object with polished or smooth-surfaces.

These prints are formed by a combination of dust. Latent prints include those which are invisible to the unaided eye and all others that are visible but only properly examined after development.

Significance

Uniqueness:- The characteristics features of a fingerprint are so unique that they are not exactly repeated in any other fingerprint or part of one.

Infallibility:- Fingerprints are now universally recognized as an infallible means of personal identification and identification of criminals.

Durability:- A fingerprint remains unchanged throughout the life of an individual.

Simplicity:-  Records of millions of persons can be kept and retrieved easily with the help of a computer. 

Searching Of Fingerprint From The Scene Of Crime

Location

  • When a criminal acts, he cannot avoid leaving clues in the form of fingerprints unless he wears gloves or something else for protection.
  • The following locations are very much common to find fingerprints:-
1.) The Crime Scene
  • Furniture, Almirah, Boxes, Glass Articles, Crockery, Fridge, Utensils, Bottles, Etc. Should Be Carefully Examined.
  • Walls, Windows, Vehicle, Floor, Doors, Light Switches, Circuit Breakers and Fuses Should Always Be Examined.
  • Good Prints Are Often Found On Glass, China Clay Articles Polished Or Painted And Other Smooth Surfaces Like Photography Paper, Negative Film, Adhesive Tape, Carbon Paper, Etc.
2.)  Point of Entry
  • If A Door Was Broken Or Forcefully Opened, Fingerprints May Be Found On The Locks, Knobs, Handles.
  • If a window was broken, search for pieces of broken glass which may contain fingerprints.
  • Fingerprints May Be Left On The Window, Window Frame, Window Steel And Jamb.
3.)  The Vehicle
  • The Transport Vehicles such as Cars, Jeeps, Motorcycles, Scooters, etc. are likely to bear fingerprint of the culprit or their occupants.
  • Steering, Wheel, Back Review Mirror, Lower Parts Of Dikki And Window Glasses, Etc. may contain fingerprints.
4.) Objects Belonging To The Culprit
  • The culprits very often leave some objects belonging to them which may have excellent chances of bearing fingerprints.
  • Such Objects May Include Shoes, Watch, Tools, Weapon Of Offence, Torch, Liquor Bottles, Poison Bottle, Gas Cutters Assembly, Container Of Fuel Oil Especially In Cases Of Arson, Etc.
5.) Human Bodies
  • Recent techniques have made possible to develop fingerprints on human bodies.
  • Such Fingerprints Are Usually Located On The Skin At Neck, Breasts, Thighs, Wrists And Ankles Regions.

When And How Is Fingerprint Analysis Used?

  • Identification of criminals whose fingerprints are found at the scene of crime.
  • Providing biometric Security
  • Identifying amnesia Victims and Unknown deceased
  • Conducting background checks
  • Identification of missing persons or in cases of kidnapping.
  • Identification of unconscious persons.
  • In mistaken identity.
  • Detection of bank forgeries.
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