powerpoints fingerprints

Sir William Herschel

Conducted studies on different ethnicities and friction ridge detail
• Documented his own fingerprints over his lifetime to prove
“permanence
first European to note the value of fingerprints for identification
• Recognized friction ridge detail is “unique” and “permanent

Alphonse Bertillon

First system using photography and physical measurements; adopted in 1883
•bertillon system
• Measurements of bony body parts (typically 12 different body parts) for identification

Henry Faulds

claimed that fingerprints did not change over time and that they could be classified for identification

Sir Francis Galton

coined eugneics, discovered loops, arches, whorls

Juan Vucetich

Fingerprinting methodology called dactyloscopy

Sir Edward Henry

Henry’s classification system: assigned numerical values to fingers

Henry Deforest

First systematic use of fingerprinting in the US 1902, established practice of fingerprinting on civil service applications in NY

Babylon (2000 B.C.)

-Archaeologists have
discovered evidence showing
fingerprints were used on clay
tablets
• Prints were considered a
unique signature or mark

China (221 B.C)

• In ancient China, fingerprints
were also used as a form of
identification on legal
documents
• It was a common practice to
“sign” documents using the
fingers or palm.

In addition to China, Japan used fingerprints as a way of
identification as early as

702 A.D

The United States did not use fingerprints as a means of
identification until

1902

Skin is considered an organ and acts as a

protective layer

Human Skin is the _____ of the human body

heaviest organ

Volar Skin-ridged (has texurized surface)

also known as friction ridge detail

Two types of skin

Smooth and volar

What was developed in-utero (friction ridge detail)

During 8th-10th week of gestation
• Fully developed at 6 months

Persistent throughout one’s lifetime (friction ridge detail)

Barring permanent scarring
• Decomposition after death

Friction Ridge Skin

-Friction ridge skin tends to
lean in the same direction
-Flexible
-When pressure is applied, it will resist slipping by rolling
over slightly this is referred to as imbrication
-Permits the skin to grip onto a surface

Premise of Friction Ridge Skin

Permanent (persistant)
-structure of skin
Unique
-during development

Volar pads (1)

At six weeks the hand is paddle-like. The fingers are scallops around its edge. Some volar pads are starting appear.

Volar pads (2)

At ten weeks the interdigital pads are prominent and the thumb has rotated. the digital pads have also become prominent.

Dr. Harold Cummins

-An Introduction to Dermatoglyphics

-found that the location and growth of the volar pad affected the friction ridge development and pattern configuration

High Volar Pad

High-centered pads are believed to form whorl- type patternn

Intermediate Volar Pad

Intermediate pads with a trend are believed to form loop-type patterns

Low Volar Pad

Low volar pads tend to form arch or low count loop patterns and can be the result of a disturbance during fetal formation.

Birth defects in volar pads

Also noted the other factors such as birth disease or birth defects may interfere with volar pad development and may also affect the friction ridges

12 areas of Dr. harold cummins

5 digits
-4 interdigital areas
-Thenar side(T)
-Hypothenar
side(H)
-Central Area(C)

*coin dermatoglyphics.

Primary Ridges

-Ridge formations found directly under surface
friction ridges

• Mirror the surface ridge and contain pore structures

Two main layers of the skin

epidermis and dermis

Epidermis

• Outer layer of the skin
• Made up of several layers of skin cells

Various layers divided into 2 groups: (epidermis)

1. . Inner layer of cells is the stratum
   Malpighian (aka: stratum mucosum)
   2. Outer layer is the stratum corneum.

___________ is made up of the basal layer, being the deepest (aka: stratum
basal or stratum germinativum) ((epidermis)

Malpighian layer

After the basal layer it is followed by_____ and then _________ (epidermis)

spinous layer (stratum spinosum) & granular layer (stratum granulosum)

The outer or surface group of cells consists of the _______and the ______ . (epidermis)

hyalin layer & horny layer .

Deepest layer of cells next to the dermis is called the_______(Generating layer )

basal layer

Basel layer is ______ (Generating layer )

one cell deep

A membrane separates the basal layer from the_______ (Generating layer )

dermis

___________ allows wastes to leave the epidermis and be removed from the dermis
Epidermis – non- vascular
(generating layer)

Membrane

template of your fingerprint!

basel layer

Due to the key role the basal layer plays in generating new skin cells, it
is often referred to as the____________

generating layer

Basel layer

Basal Epidermal cells –
columnlike in shape
• Divide in the generating
layer and start a slow
migration toward the
surface as they are
displaced by newly
generated cells

-• Trip to the surface takes
approx. 1 month but
numerous variables can
alter that rate

-As they progress to the
top, the cells flatten
• Cells at the top are
continually displacing
surface cells which are
shed when the cell
junction points break
down or through abrasion

cells held together with a substance called

desmosomes

Dermis

-Inner layer of the friction skin

-Vascular with numerous blood vessles, lymphatics, various glands and tactile nerves

-Very strong density

Loose connective tissue composed of________ (dermis)

Fibrous protiens

what is the function of dermis?

feeding nutrients to the outer layer of friction skin as well as giving physical protection to the internal body

Dermis is often called the ______

true skin

Surface of the dermis is covered with blunt peg-like formations called______ and Nerve endings are contained in the__________

dermal papillae

Dermal papillae contain_________ to feed oxygen and food supplies to the generating layer of the epidermis and to remove waste.

capillary loops

Injury/Disease

_________ that penetrates the skin to the dermal papillae level can damage the epidermal basal layer infrastructure

destroy the ability of the basal layer to regenerate cells in the damaged area – thus resulting in a __________

Scar

Latent Prints

also known as crime scene prints. These are hidden fingerprints often found at the
scene of a crime and need to be developed so they are visible.

Patent print

a visible print. The friction ridge detail is visible due to some type of transfer
medium such as blood, ink, or paint

Plastic Print

referred to as impressed prints. Friction ridge detail is idented into soft pliable
such as wax, wet paint, butter, or gum. These types of prints are three-dimensional.

Known print

referred to as exemplar prints. These are intentional prints collected from a
person typically using ink, black fingerprint powder, or livescan

Recording friction ridge detail

Known prints aka examplers

-Standard 10 print card

-palm print exemplars

-major case prints

-hands and feet

-Elimination prints

Deliberate recordings of friction ridges (known prints)

black ink, black powders, electronically (livescan)

record all areas of fricition skin (known prints)

fingers, plams, toes/feet (if applicable)

Very important to take complete, clear recordings of known prints for comparison purposes (known prints)

-Stay in control. Guide your subject.
-Do not over or under ink
- Do not use too much pressure

supplies needed to record friction ridge detail

-black ink pad

-elimination or two point card for recording fingers

-palm print card or plain piece of paper for recording prints

-hand wipes or paper towels

critical areas of a fingerpint comparison purpose

delta and core

delta

point on a ridge at or nearest to the point of divergence (tri-radius)

Core

approximate center of a fingerprint pattern

3 basic pattern types

arch, whorl and loop

Arch

-5%

No deltas or cores
The ridges enter from one side of the finger, rise in the center, and exit out the
other side of the finger

Tented arch

The rise in the center is more pronounced and has a “tent-like" peak

Plain arch

ridges flow smoothly with a gentle rise in the center

Whorls

-30%

-circular, spiral, elliptical

-at least two deltas
- Each delta will have a recurve in front of it

- regardless of the sub-pattern type, have two
deltas

Plain Whorl

One or more ridge that make a complete circle or circuit

Double loop whorl

Two separate loop formations that intertwine

central pocket loop whorl

One or more ridges that make a complete circuit, but it includes a
loop in the enclosed area

Accidental whorl

Multiple whorl types within one pattern that does not fit into one of the sub-pattern types above

Loop

-65%

-Only one delta
-A ridge that goes out or tends to go out the same side from
which it entered
-At least one ridge that crosses a line drawn between the
core and the delta

Radial Loop

ridges come from the thumb side (radial bone)
recurve and go out same side
-Loop opens towards the thumb side of the hand

-ridges flow in the direction of the thumb

Ulnar loop

-ridges flow towards the little finger or “ulnar
side” of the hand
-Ulnar loops are more common than radial loops

-ridges flow in the direction of the little finger

Within those patterns are discriminating features __________

Ridge events

Ridge characteristics are known as

minutaie or points (ridge events)

Ridge count____from the ridge ending to the bifurcation is

3

A finger print may contain ____ to ____ minutiaes

75 to 125

Lot of infromation in a single print or palm____

ridge flow, ridge path, and ridge shapes

Various types of prints

inked, patent, plastic and latent

Latent means______

hidden or undeveloped

Latnet prints _____ moisture

98-99%

_______ are one of the oldest and most common types of physical evidence left behind at a scene

Fingerprints

The skin has deposits of oil and perspiration that
normally coat the surface. When a hand comes into
contact with a surface, there is a transfer thus an
impression is ______ left behind.

usually (Locards exchange theory)

Locards exchnage principle

whenever two objects come into contact, a transfer of material will occur between them.

Factors that effect how prints are deposited

-amount of contact/time

-Condition of the surface or objects

- Environment

equipment for developing friction ridge detail

-lifting tape

-lift cards

-fingerprint powder (black, mangentic, fluorescent)
-Brush
- finberglass for black fingerprint powder

-magnetic wand for mangentic powder

Black, bi-chromatic, gray, white, or silver

Used on the majority of surfaces
 Color of powder used depends on the color of the surface (contrast)

Black, bi-chromatic, or silver magnetic powder

-Used on glossy surfaces; glass, tile, and plastics
-Used on waxy surfaces; drink cups, magazine covers, and some types
of fruit
-Can be used to expose “indented writing”

Processing a crime scene or evidence for latent prints

Visual examination prior to processing
 Use black fingerprint powder or magnetic fingerprint
powder depending on the surface
 Fingerprint powder is only used on non-porous items such
as windows and cans.
 Porous items can be processed for latent prints; however,
this should be done in the CSI Lab. Chemicals are used
during processing and typically evidence cannot be
returned.

Sample documenation

I conducted latent print processing using black fingerprint powder on the
following surfaces/items: exterior/interior driver’s door, rear view mirror,
exterior trunk lid, and soda can in cup holder.
Two (2) lift cards were collected. One (1) lift card was collected from the
rear view mirror and one (1) lift card from the interior driver’s door.
Upon returning to the CSI Unit, the lift cards were booked into Property
and are awaiting analysis

Fingerprint databases

Automated Fingerprint Identification System (AFIS)
-Local
-State
-Federal (Next Generation Identification (NGI) formerly IAFIS)
-Department of Homeland Security (DHS)
-Interpol

Latent prints are________, just because an item was touched does not mean that a print will be left behind.

chance impressions

The absence of latent prints on an item may be due to several factors____

each depending on conditions existing before, during,
and after the finger(s) or hand(s) touched or handled the surface

four deposition factors

•Sufficient residue (matrix)
•Suitable surface
•Manner of contact/touch
•Environmental conditions

Sufficient residue (matrix)

-There must be sufficient residue on an individual's fingers to leave
an adequate latent print; this could be sweat, oils, or another type
of contaminant.
-If there is too much residue, the residue will likely fill in the
furrows and make ridges indistinguishable.
-The opposite is detrimental as well; if there is not enough residue,
the examiner may not be able to develop the print

Suitable Surface

-Most conducive surface for a latent print is a smooth,
clean, and flat surface.
A surface that is textured, grooved, or dirty/dusty
makes developing a print more difficult

Environmental Factors

Latent print residue is approximately 98% moisture.
Heat can affect the development of prints
(evaporation)
Windy conditions may also present a challenge
when processing for prints

Manner of contact

-Amount of time an item is held or touched; good contact
is necessary
-How an item is held or touched; too much pressure can
cause distortion or twisting, or excessive grabbing of an
object may cause multiple, overlapping impressions

Types of latnet print development

physical and chemical