Fiber Evidence Quiz

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Questions and Answers

Why are fibers considered class evidence?

They are mass-produced

Where can fibers come from?

Clothing, coats, carpet, furniture, curtains, bedding, insulation, rope

What is direct transfer?

The passing of evidence from victim to suspect or vice versa

What is secondary transfer?

The transfer of evidence from a source to a person (suspect), and then to another person (victim) Signup and view all the answers

What percentage of fibers is lost after 24 hours?

95% Signup and view all the answers

When using fibers as evidence, what do forensic scientists want to determine?

Type of fiber, fiber color, number of fibers found Signup and view all the answers

What is the type of fiber that indicates composition and uniqueness?

Type of fiber Signup and view all the answers

How can fiber color help in forensic investigations?

Can help with location or dyes that were used during production Signup and view all the answers

What does a higher number of fibers found suggest?

More fiber could suggest a more violent crime or longer period of contact Signup and view all the answers

What is the first method of fiber collection?

Visual search Signup and view all the answers

What is the fiber produced from rabbit hair?

Angora Signup and view all the answers

What is the tight lengthwise yarn in a weave pattern?

Warp Signup and view all the answers

What macromolecule are animal fibers made out of?

Protein Signup and view all the answers

What are the fibers that are produced from a raw material such as coal and wood pulp that is spun together in a factory?

Synthetic Signup and view all the answers

Which carbohydrate are plant fibers?

Cellulose Signup and view all the answers

What are envelopes and paper made from?

Mamilia leaves or plants Signup and view all the answers

What are the classifications of fibers?

Fiber -> yarn -> textile Signup and view all the answers

List 6 types of hair.

Head hair, eyebrow & eyelashes, beard & mustache hair, underarm hair, body hair, pubic hair Signup and view all the answers

What are fibers?

Trace materials that are used in criminal investigation to mainly establish location and a timeline Signup and view all the answers

What is thread count?

The number of threads that are packed together for any given amount of fabric Signup and view all the answers

Name 3 natural fibers.

Animal, plants, and minerals Signup and view all the answers

What is a good alternative to rayon because it is less polluting?

Acetate Signup and view all the answers

What is an inexpensive synthetic fiber that tends to ball easily?

Acrylic Signup and view all the answers

What is the most durable man-made fabric that is extremely lightweight?

Nylon Signup and view all the answers

What is a lightweight but warm, soft, and resilient fabric?

Polyester Signup and view all the answers

What is the first man-made fiber and also the most common synthetic fiber?

Rayon Signup and view all the answers

What are fibers made from cellulose esters derived from cellulose then modified?

Regenerated fibers Signup and view all the answers

What fiber has extreme elastic properties?

Spandex Signup and view all the answers

What are fibers that are totally man-made from petroleum plastics?

Synthetic polymer fibers Signup and view all the answers

List 2 mineral fibers.

Fiberglass & asbestos Signup and view all the answers

What are the four patterns of medulla?

None, fragmented, continuous and interrupted Signup and view all the answers

Why is asbestos used?

To insulate and to serve as a fire retardant Signup and view all the answers

What is sisal?

A plant fiber used for making rope Signup and view all the answers

Where is sisal found?

It is found in a desert plant Signup and view all the answers

What is hemp?

<ul> <li>Coarser and stiffer than flax</li> <li>Longest fibers from outer range of stalk</li> <li>Strong (useful as twine)</li> <li>Commercial production not allowed in US</li> <li>Environmentally friendly</li> </ul> Signup and view all the answers

Where is hemp found?

In the stem Signup and view all the answers

Study Notes

Fiber Evidence Overview

Fibers are considered class evidence due to mass production, making it difficult to link a specific fiber to a unique source.
Common sources of fibers include clothing, carpets, furniture, curtains, bedding, insulation, and ropes.

Types of Fiber Transfer

Direct Transfer: Evidence is passed from victim to suspect or vice versa.
Secondary Transfer: Evidence is transferred from a source to a person (suspect) and then to another person (victim).

Fiber Loss and Forensic Analysis

Approximately 95% of fibers can be lost within 24 hours after a crime.
Forensic scientists aim to identify the type of fiber, its color, and the number of fibers found during investigations.

Characteristics of Fibers

Type of Fiber: Determined by composition and uniqueness.
Color: Aids in determining location or dyes used during production.
Number of Fibers: A higher count may indicate a more violent crime or prolonged contact.

Methods of Fiber Collection

The first method employed for fiber collection is a visual search.

Types of Fibers and Their Composition

Animal Fibers: Made of protein (e.g., Angora from rabbit hair).
Plant Fibers: Composed of cellulose (e.g., sisal used for ropes).
Synthetic Fibers: Result from processes involving raw materials like coal and wood, including fibers such as nylon and polyester.

Fiber Classifications and Properties

Fibers are classified as follows: Fiber → Yarn → Textile.
Thread count refers to the number of threads per unit area in fabric, commonly noted for bed sheets.

Types of Natural and Synthetic Fibers

Natural Fibers: Derived from animals (e.g., wool), plants (e.g., cotton, hemp), and minerals (e.g., asbestos, fiberglass).
Synthetic Fibers: Include man-made materials like rayon, nylon, polyester, and spandex.
- Rayon is the first and most common synthetic fiber.
- Acetate is noted for being less polluting than rayon.
- Acrylic is an inexpensive fiber that can easily ball up.

Specialized Fiber Information

Spandex exhibits extreme elasticity.
Regenerated fibers are modified cellulose fibers.
Asbestos is used for insulation and fire retardation, while fiberglass is another mineral fiber with different applications.

Other Notable Fiber Facts

Chessboard is a specific weaving pattern, though more details on it are not provided.
Hemp, a strong plant fiber from the stalk, is coarser than flax, commercially produced under strict regulations in the U.S.

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Description

Test your knowledge on fiber evidence in forensic science. This quiz covers topics such as the classification of fibers, transfer types, and sources of fibers. Perfect for students studying forensic science or criminal investigation.