Fingerprint

Fingerprints are one of the oldest, most reliable and most widely used forms of personal identification in forensic science. Every individual possesses a unique arrangement of ridges and furrows on the skin of the fingertips that remains unchanged throughout life, making fingerprints an invaluable tool for linking a suspect to a crime scene.

The study of fingerprints, known as dactyloscopy, classifies patterns into three fundamental types – loops, whorls and arches – which are further divided based on ridge characteristics called minutiae. At a crime scene, latent prints are developed using powders, chemical reagents such as ninhydrin and cyanoacrylate fuming, and are then lifted, photographed and compared against known records or automated databases (AFIS).

Types of Fingerprint Patterns

The three primary pattern types are Loops (ulnar and radial), Whorls (plain, central pocket, double loop and accidental) and Arches (plain and tented). Identification is confirmed by matching individual ridge characteristics known as minutiae such as ridge endings, bifurcations and islands.

Development of Latent Prints

Latent prints, which are invisible to the naked eye, are developed using physical methods such as fingerprint powders and magnetic powders, and chemical methods including ninhydrin, silver nitrate, iodine fuming and superglue (cyanoacrylate) fuming, followed by lifting and preservation for comparison.