Fiber + Hair

Fibers may be analyzed using this test, but only if there are multiple fibers of the same type

Fibers may be analyzed using this test, but only if there are multiple fibers of the same type

Burn

A type of natural fiber that comes from a sheep

wool

A type of transfer that occurs when fiber evidence moves from a source to a person/object and is then transferred to another person/object

Secondary

Categorized as a regenerated fiber that is made of polymers

synthetic

A method of collecting fiber evidence form a crime scene or victim

Adhesives

A flexible, flat material made by interlacing threads/fibers

textile

A device that is used to observe and identify fiber evidence in forensics

microscope

Fiber evidence is classified in this way

Class

One of the three types of natural fibers

minerals

Fibers that are derived from plants, animals, or minerals

Natural

A type of fiber transfer that occurs when a fiber moves from a source to a person or object

Direct

A type of weave pattern characterized by a weft that is woven over 3 or more warps and then under one

Twill

Fiber

the smallest indivisible unit of a textile

Textile

a flexible, flat material made by interlacing yarns (or "threads")

Fibers often fall off and are picked up during normal activities. This is an example of _____________ Principle.

Locard's

Very small fibers easily shed from most textiles and can become ________

trace evidence

Fiber evaluation can show such things as the _______ of fiber, its ________, the possibility of ___________, location of suspects, and point of ____________.

type, color, violence, origin

Direct transfer

fibers are transferred directly from victim to suspect or suspect to victim

secondary transfer

fibers are transferred from a source, to the suspect and then to a victim (or from a source, to a victim and then to the suspect)

Fibers can be collected by:

Vacuuming, adhesive removal, forceps

Fibers can be classified as:

natural or synthetic

Natural fibers

derived from animals, plants and minerals

Synthetic fibers

man-made fibers produced in a laboratory. The fibers are produced by joining many monomers together to form polymers

Plant fibers can _______ water

absorb

Plant fibers are ________ in water

insoluble

Plant fibers are very ___________ to damage from harsh chemicals

resistant

plant fibers can only be dissolved by strong _______

acids

Plan fibers can be common at crime scenes because they become _______ over time

Brittle

List 3 examples of plant fibers

Cotton, coir, hemp

List 4 examples of animal fibers and their origin

Wool- sheep

Cashmere

Angera- rabbits

Silk- caterpillar cocoons

List 2 examples of mineral fibers

Fiberglass & abestos

Fiberglass

fibrous form of glass

Abestos

A naturally occurring mineral with a crystalline structure

List 5 examples of synthetic fibers

Polyester, nylon, acrylic, acetate, rayon/viscose

Polyester

found in "polar fleece," wrinkle-resistant, and not easily broken down by light or concentrated acid; added to natural fibers for strength

Nylon

easily broken down by light and concentrated acid; otherwise similar to polyester

Acrylic

inexpensive, tends to "ball" easily, and used as an artificial wool or fur

Acetate

Silky, luxurious appearance. It dries easily and resists absorbing moisture.

rayon/viscose

Semi-synthetic with a high luster and bright sheen

warp

vertical threads

Weft

horizontal threads

Characteristics of synthetic burn analysis

Melts, solidifies when cooled, gives off chemical odor

Characteristics of natural burn analysis

Shrinks away from flame, burns to ash, smells like singed hair

Hair can be classified as?

class and individual evidence

without the follicle it would be considered as?

class evidence

with the follicle it would be considered as?

individual evidence

Hair can be collected by?

plucking, shaking, scrapping surfaces

macroscopic characteristics

length, colour, curliness

microscopic characteristics

pattern of medulla, pigmentation of the cortex, types of scales on the cuticle

function of hair

regulates temp, protects skin, acts as a sensory organ

2 parts of the hair

follicle and shaft

3 layers of the hair

cuticle outer, cortex middle , medulla inner

cuticle function (outer)

To protect the inner layer of the shaft

cortex function (middle)

makes up the largest part, contains pigmentation (melanin)

medulla function (inner)

different classifications absent, continuous, interrupted, fragmented

Hair regions

head, eyebrow/lash, beard, pubic area, body, underarm

characteristics of human hair

pigmentation is constant, thin 1/3, has overlapping scales

characteristics of animal hair

abrupt color changes, very wide

medullary index

if the index is greater then its animal hair then .5 its animal, if the index is less then .33 then its human hair

What protein keeps the hair strong?

keratin

keratin also helps?

make the hair resistant to decomposition.

The journey of evidence from the crime scene to the courtroom is a meticulous process vital for the pursuit of_______?

justice

Once collected, evidence undergoes analysis by forensic _______ who employ various techniques to extract valuable information

experts

This could involve DNA testing, ballistics analysis, or forensic accounting, depending on the nature of the______

case

The findings of these analyses are documented in detailed _______ that provide crucial insights into the circumstances surrounding the crime.

reports

Once ________ evidence is collected, a person might be charged with a crime

sufficent

The U.S. Constitution was signed in________

1787

What are the three branches of government?

Legislative, Executive, Judicial

congress added?

10 amendments

10 amendments are called the?

Bill of Rights

What did the 6th Amendment do?

right defense

the 6th amendment includes

impartial jury, criminal charges, confront witness, legal representation

jury listen to???

defense and prosecution

A jury hears information about the physical and circumstantial evidence and hears?

testimony from witness

the jury makes either a choice of the suspect being?

innocent or guilty

who were Frye vs. United States and Daubert vs. Merrell Dow Pharmaceuticals

were two influential cases that resulted in major changes in the field of Forensics.

the frye standard was

provided a Conservative approach to admitting scientific evidence

the daubert was

where evidence had to be reliable and relevance