Unit 6 Flash Cards

Essential Concepts

  • Three Major Fingerprint Patterns

    • Arches: No deltas, ridges enter on one side and exit on the other.

    • Loops: One delta, ridges enter and exit on the same side.

      • Subtypes: Ulnar loop, Radial loop.

    • Whorls: Two deltas, circular or spiral ridges.

      • Subtypes: Plain whorl, Central pocket loop, Double loop whorl, Accidental whorl.

  • Minutiae Patterns

    • Bifurcations

    • Ending Ridges

    • Dots

    • Short Ridges

    • Enclosures/Islands

  • Types of Fingerprint Impressions

    • Patent: Visible (e.g., blood, ink).

    • Plastic: 3D impressions in soft materials.

    • Latent: Invisible, requires development methods.

  • Methods for Developing Fingerprints

    • Nonporous Surfaces

      • Cyanoacrylate Fuming ("Superglue").

      • Fingerprint Powders.

    • Porous Surfaces

      • Ninhydrin: Reacts with amino acids.

      • Crystal Violet: Stains adhesive materials.

    • Other Methods

      • Iodine Fuming: Temporary visualization.

      • Silver Nitrate: Reacts with salts.

  • Documenting Results

    • Photography is used to capture developed prints.



History of Fingerprints

  • Francis Galton: Established individuality and permanence of fingerprints.

  • Edward Henry: Developed classification system (Henry Classification).

  • Alphonse Bertillon: Anthropometry for identification (replaced by fingerprints).



Fingerprint Databases

  • Integrated Automated Fingerprint Identification System (IAFIS): FBI database for matching fingerprints.

  • Next Generation Identification (NGI): Advanced biometric system.



Key Concepts

  • Minimum ridge characteristics for a match: No universal standard, but 8-16 points often used.

  • Bertillon System: Early identification based on body measurements (now obsolete).

  • Primary Classification Number: Calculated using a 10-print card.



Vocabulary Terms

  • Dactylography/Dactyloscopy: Study of fingerprints.

  • Dermis/Epidermis: Skin layers involved in ridge formation.

  • Delta: Triangular area in loop and whorl patterns.

  • Fuming: Chemical development of latent prints (e.g., Cyanoacrylate, Iodine).

Anthropometry: Measurement of the human body for identification