Forensic Science: Fingerprint Evidence

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Why are fingerprints considered individual evidence rather than class evidence?

Because no two fingerprints are the same.

What are fingerprints composed of, and how are they deposited?

They are composed of patterns and ridge-like characteristics and deposited by transferable oils such as perspiration.

What is the difference between a fingerprint pattern and a ridge characteristic?

Fingerprint patterns consist of arches, loops, and whorls, while ridge characteristics are the minutiae.

How can fingerprint patterns be changed?

By scarring or burns. Signup and view all the answers

What is the most common type of fingerprint pattern?

Loops. Signup and view all the answers

What is the least common fingerprint pattern?

Arches. Signup and view all the answers

A loop pattern that opens toward the thumb is known as a __________.

radial loop. Signup and view all the answers

All whorl patterns have __________ deltas.

<ol start="2"> <li></li> </ol> Signup and view all the answers

What is meant by a latent print, and how can one be developed?

A latent print is an invisible fingerprint that can be developed by dust or powder. Signup and view all the answers

Explain what IAFIS is and how it is used.

The Integrated Automated Fingerprint Identification System is used to connect a worldwide fingerprint database. Signup and view all the answers

How is the 'final verification' made using the AFIS system?

The certified latent print examiner will make the final decision on who it belongs to. Signup and view all the answers

What is the difference between a plastic, latent, and visible fingerprint?

Visible prints are left in substances like paint or blood; plastic prints are left in soft surfaces like putty; latent prints are left in bodily oils and may require treatment to be visualized. Signup and view all the answers

What is the significance of the Donald and Ronald Smith case?

The significance is that the fingerprints weren't verified and many errors were made in the case, resulting in the US government being sued for 2 million dollars. Signup and view all the answers

What is a fingerprint?

An imprint made by ridge patterns on the tip of a finger or the characteristic pattern of DNA fragments. Signup and view all the answers

What are microns?

One-millionth of a meter or one-thousandth of a millimeter. Signup and view all the answers

What is dactyloscopy?

The study of fingerprints. Signup and view all the answers

What is anthropometry?

The study of human body measurements. Signup and view all the answers

What is a loop in terms of fingerprint patterns?

A fingerprint pattern in which the ridge pattern flows inward and returns in the direction of the origin. Signup and view all the answers

What is a whorl?

A fingerprint pattern with at least two deltas and a core. Signup and view all the answers

What is a core in fingerprint patterns?

An area found near the center of all loop and whorl patterns. Signup and view all the answers

What are deltas in fingerprint patterns?

Triangular areas found in all loop and whorl patterns. Signup and view all the answers

What is an arch in fingerprint patterns?

The least common and simplest fingerprint pattern where all ridges enter one side and exit the other without deltas or cores. Signup and view all the answers

What is minutiae?

Ridge endings, bifurcations, enclosures, and other ridge details which must match in two fingerprints to establish their common origin. Signup and view all the answers

What is a plastic print?

A three-dimensional print made from indentations in soft material such as fresh paint or putty. Signup and view all the answers

What is a visible print?

A fingerprint left by a finger that has touched blood, paint, ink, or similar substances. Signup and view all the answers

What are latent prints?

Fingerprints made by the deposit of perspiration or body oils, invisible to the naked eye until developed. Signup and view all the answers

What is Ninhydrin?

A biochemical reagent used to detect free amino and carboxyl groups and proteins in peptides. Signup and view all the answers

What is a bifurcation in fingerprint analysis?

A common minutiae shaped like a two-prong fork. Signup and view all the answers

What is biometrics?

Using measurable biological characteristics for authentication or identification. Signup and view all the answers

Study Notes

Fingerprint Characteristics

Fingerprints have class characteristics including loops, whorls, arches, cores, deltas, bifurcations, ridges, and spurs.
Considered individual evidence since no two fingerprints are identical.

Composition and Deposition

Composed of ridge patterns and characteristics.
Deposited through oils from perspiration and other bodily fluids.

Fingerprint Patterns vs. Ridge Characteristics

Patterns: Arches, loops, and whorls.
Ridge characteristics: Specific minutiae used for identification.

Changeable Fingerprint Patterns

Can be altered due to scarring or burns.

Common and Rare Patterns

Most common pattern: Loops.
Least common pattern: Arches.

Loop Types

Radial loop: Loops that open toward the thumb.

Whorl Characteristics

All whorl patterns contain two deltas.

Latent Prints

Invisible fingerprints that require development to be visible, usually with dust or powder.

IAFIS Overview

Integrated Automated Fingerprint Identification System connects a global fingerprint database.

Final Verification in AFIS

Conducted by a certified latent print examiner for accuracy in identification.

Types of Fingerprints

Visible fingerprints: Clearly seen, left in substances like blood or paint.
Plastic prints: Indentations in soft surfaces (e.g., putty).
Latent prints: Invisible prints made by body oils, requiring treatment.

Notable Case: Donald and Ronald Smith

Case significance lies in verification errors leading to a lawsuit against the US government for $2 million.

Definitions

Fingerprint: Ridge pattern imprint from a finger's tip.
Micron: One-millionth of a meter; one-thousandth of a millimeter.
Dactyloscopy: Study of fingerprints, originating from Greek 'daktulos' (finger).
Anthropometry: Study of human body measurements, derived from Greek 'anthropos' (man).

Fingerprint Patterns Details

Loop: Ridge pattern flows inward and returns toward the origin.
Whorl: Pattern includes at least two deltas and a core.
Core: Central area found in loops and whorls.
Deltas: Triangular areas in loop and whorl patterns.
Arch: Simplest fingerprint pattern with ridges entering one side and exiting the other, lacking delta or core.

Minutiae and Print Types

Minutiae: Detailed ridge features for fingerprint matching.
Plastic print: Three-dimensional impressions in soft materials.
Visible print: Fingerprints left in substances like blood or paint.
Latent prints: Invisible impressions from sweat or oils until developed.

Ninhydrin

A reagent used to detect amino and carboxyl groups in proteins, producing a purple color known as Ruhemann's purple.

Bifurcation

A common minutiae pattern resembling a two-prong fork.

Biometrics

Utilizes measurable biological characteristics for authentication or identification processes.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the characteristics of fingerprints and why they are classified as individual evidence. It discusses the composition of fingerprints and their deposition methods. Test your understanding of forensic science concepts related to fingerprint analysis.