Forensics Fingerprints Flashcards

Questions and Answers

What are the three principles of fingerprints?

Fingerprints are individual characteristics, unchanged throughout life, and have individual ridge patterns that classify them.

Which of the following are kinds of fingerprint patterns?

Stripes

Whorls (correct)

Loops (correct)

Arches (correct)

What are the types of arches?

Plain arch (correct)

Radial arch

Ulnar arch

Tented arch (correct)

What are the types of loops?

Accidental loop Signup and view all the answers

What are the types of whorls?

Plain whorl Signup and view all the answers

What percentage of fingerprints are loops?

60% Signup and view all the answers

What percentage of fingerprints are whorls?

35% Signup and view all the answers

What percentage of fingerprints are arches?

5% Signup and view all the answers

What is ridgeology?

The study of the uniqueness of friction ridge structures and their use for personal identification. Signup and view all the answers

What are minutiae in the context of fingerprints?

Points where the ridge structure changes, representing small characteristics or details. Signup and view all the answers

What is the UK standard for points of identification in fingerprints?

Min. 16 Signup and view all the answers

What is the Australia standard for points of identification in fingerprints?

Min. 12 Signup and view all the answers

What does AFIS stand for?

Automated Fingerprint Identification System Signup and view all the answers

Which of the following are examples of ridge characteristics?

Core Signup and view all the answers

What are latent prints?

Impressions left by friction ridge skin on a surface, requiring enhancement. Signup and view all the answers

What is the most common hair used in brushes for fingerprint analysis?

Camel hair Signup and view all the answers

When was the first U.S. crime solved using fingerprints?

1910, Chicago Signup and view all the answers

How far back do fingerprints date?

1000 years ago to China Signup and view all the answers

Where did America get its fingerprint methods from?

Europe 17th-18th centuries Signup and view all the answers

Who was the first European to use fingerprints as an identification method?

Sir William Herschel Signup and view all the answers

Who wrote a book called 'Fingerprints' and when?

Sir Francis Galton, 1892 Signup and view all the answers

When was the first crime solved with fingerprints?

1892, Argentina Signup and view all the answers

What are patent prints?

Visible prints that do not require enhancement Signup and view all the answers

What are plastic prints?

Impressions left on a soft, receiving surface Signup and view all the answers

What is the most important factor in developing a print?

Surface Signup and view all the answers

Which of the following are physical methods of print development?

Small Particle Reagent (SPR) Signup and view all the answers

What is powder dusting?

A method done on a smooth, nonporous surface (plastic/metal). Signup and view all the answers

What is a magnetic brush used for?

A method done on a smooth, nonporous surface. Signup and view all the answers

What is a Small Particle Reagent (SPR) used for?

A method done on a surface that was previously wet/is wet. Signup and view all the answers

What is Mikrosil used for?

A method done on an irregular surface. Signup and view all the answers

Which of the following are chemical methods of print development?

Cyanoacrylate (super glue) Signup and view all the answers

What does iodine fuming do?

Reacts with lipids, doesn't last long on nonporous surfaces. Signup and view all the answers

What does Ninhydrin react with?

Amino acids, usually develops prints in good quality. Signup and view all the answers

What does Cyanoacrylate (super glue) do?

Vaporizes with fumes on a nonporous, solid surface. Signup and view all the answers

Which of the following are other methods of print development?

Alternate light source Signup and view all the answers

What special methods are used for developing bloody fingerprints?

Enhanced with peroxidase which doesn't interfere with blood type. Signup and view all the answers

What surface should you use Ninhydrin on?

Paper/cardboard Signup and view all the answers

What is magnetic powder used on?

Plastic surfaces. Signup and view all the answers

What surface is Small Particle Reagent (SPR) used on?

Wet surface. Signup and view all the answers

What surface is Mikrosil used on?

Leather/vinyl. Signup and view all the answers

What is peroxidase used for?

Enhancing bloody fingerprints. Signup and view all the answers

What type of wood is Ninhydrin used on?

Untreated wood. Signup and view all the answers

What type of wood is standard powder brush used on?

Treated wood. Signup and view all the answers

Study Notes

Fingerprints Overview

Fingerprints are unique to each individual and remain consistent throughout life.
They consist of specific ridge patterns classified into different categories.

Types of Fingerprint Patterns

Three main types: arches, whorls, and loops.
Arches include plain arch and tented arch.
Loops consist of radial loop, ulnar loop, double loop, and accidental loop.
Whorls include plain whorl and central pocket whorl.

Fingerprint Distribution Statistics

Loops constitute approximately 60% of fingerprint patterns.
Whorls account for around 35%.
Arches make up about 5%.

Ridge Characteristics and Identification

Ridgeology is the study focused on the unique features of friction ridge structures for identification purposes.
Minutiae refers to the specific points where ridge structures alter, essential for identification.
Identification relies on matching points of similarity between different prints.
The UK requires a minimum of 16 points for identification.
Australia mandates a minimum of 12 points for identification.

Automated Fingerprint Identification System (AFIS)

AFIS stands for Automated Fingerprint Identification System, overseen by the FBI (IAFIS).
It allows for nationwide scanning and searching of fingerprints.

Latent and Visible Prints

Latent prints are impressions made by friction ridge skin and require enhancement for visibility.
Patent prints are visible without the need for enhancement.
Plastic prints are impressions left in soft materials, also requiring no enhancement.

Development Methods for Fingerprints

Surface type is crucial for successful print development.
Physical development methods include powder dusting, magnetic brush, Small Particle Reagent (SPR), and Mikrosil.
Chemical methods of development encompass iodine fuming, ninhydrin, and cyanoacrylate (super glue).
Additional methods rely on alternate light sources and specific chemical reactions for print enhancement.

Specific Development Situations

Bloody fingerprints can provide timeframes for crimes when enhanced with peroxidase, without affecting blood type.

Material Suitability for Development

Ninhydrin is effective on paper/cardboard and untreated wood.
Magnetic powder works best on plastic surfaces.
SPR is designed for wet surfaces.
Mikrosil is suited for leather/vinyl surfaces.
Peroxidase is used in developing prints from blood samples.
Standard powder brush is utilized on treated wood.

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Description

Test your knowledge of fingerprints with these flashcards! Learn about the characteristics, types, and patterns of fingerprints, including arches, whorls, and loops. Perfect for forensic science enthusiasts or students studying forensic techniques.