Key Concepts in Forensic Science and Fingerprint Analysis

Father of forensic toxicology

Mathieu Orfila

First scientific system of personal identification

Alphonse Bertillion in 1879

First definitive study of fingerprints and their classification

Francis Galton

Procedure to determine blood type from dried bloodstains

Leone Lattes

Used a comparison microscope to determine if a particular gun fired a bullet

Calvin Goddard

Fundamental principles of document examination

Albert Osborn

Utilized microscopy and other analytical methodologies to examine evidence

Walter McCrone

First treatise describing the application of scientific principles to criminal investigation

Hans Gross

Incorporated Hans Gross' principles into a workable crime laboratory

Edmond Locard

Locard's Exchange Principle

When a criminal comes in contact with an object or person, a cross-transfer of evidence occurs

First responsibility of the first responding police officer upon arrival at a crime scene

Acquiring medical assistance for injured victims

Why medical personnel should avoid disturbing evidence at a crime scene

It may compromise the integrity of the evidence

What to do after detaining potential suspects or witnesses

Secure the crime scene

Requirement to secure the crime scene effectively

Using only verbal warnings to keep people away

Who may be restricted from accessing the crime scene

Civilians and unauthorized personnel

Type of log to be kept at the crime scene

A detailed log of personnel movements, including names and times

What investigators should avoid doing at the crime scene

Altering the crime scene

How to handle the area surrounding the crime scene

It must be secured to prevent contamination of evidence

Three methods for crime scene recording

Notes, Photography, and Sketches

Ideal approach for recording a crime scene

Combining notes, photography, and sketches

What might prohibit the use of photography at every crime scene

Personnel and monetary limitations

Method of recording a crime scene that involves creating a visual representation

Sketches

Importance of notes in crime scene recording

They document observations and actions taken by investigators

Primary function of the Henry System

To classify and organize fingerprint records

Year the Henry System was adopted by Scotland Yard

1901

How the Henry System classifies ridge patterns on all 10 fingers

By converting them into a series of numbers and letters arranged in a fraction

Reason the Henry System was modified by the FBI

Because of an increase in the number of fingerprints

What the primary classification in the FBI system provides

The first classification step in the FBI system

Purpose of AFIS technology

To scan and digitally encode fingerprints for high-speed processing

How AFIS aids in classifying fingerprints

By converting fingerprint images into digital minutiae

What digital minutiae in AFIS contain information about

Ridges at their points of termination (ridge endings) and branching (bifurcations)

Ridge endings in fingerprint analysis

The points where ridges stop or terminate

Bifurcation in fingerprint terminology

The branching of a single ridge into two ridges

Ultraviolet image converter for detecting latent fingerprints

The Reflected Ultraviolet Imaging System (RUVIS)

Iodine fuming involves heating iodine crystals that transform it into

Vapors (sublimation)

What happens to iodine prints over time

They fade

What should be done immediately after developing iodine prints

They need to be photographed immediately

What ninhydrin reacts with in latent prints

Amino acids

Color produced when ninhydrin reacts with amino acids in latent prints

Purple-blue

Purpose of the Physical Developer

To develop prints when other chemical methods are ineffective

Physical Developer is especially useful for developing prints on

Wet porous objects

Definition of latent prints

Invisible fingerprints caused by the transfer of perspiration or oils

How visible prints are created

When fingers touch a surface after being in contact with a colored material

Plastic prints

Ridge impressions left on a soft material

Examples of soft materials where plastic prints can be found

Putty, wax, soap, or dust

Type of fingerprint considered invisible to the naked eye

Latent prints

What causes latent prints to form on an object

The transfer of body perspiration or oils from finger ridges

What is required to visualize latent prints on a surface

Special lighting or chemicals

Fingerprint pattern characterized by ridges that enter from one side, curve around, and exit from the same side

Loop

If a loop fingerprint opens toward the little finger, it is categorized as

Ulnar loop

ACE-V is a four-step process to identify and individualize a fingerprint

Analyze, Compare, Identify, Verify

First step in the ACE-V process

Analysis

Three levels of analysis during the Comparison step

Level 1, Level 2, and Level 3

Level of comparison that involves the general ridge flow and pattern configuration

Level 1

Level 1 comparison

Focuses on locating and comparing ridge characteristics or minutiae

Level 3 comparison

Examines ridge pores, breaks, creases, scars, and other permanent minutiae

Identification step conclusions

Identification, Exclusion, and Inconclusive

Identification conclusion

Indicates the latent print and exemplar are from the same source

Verification step purpose

To confirm the examiner's conclusion by a second examiner

ACE-V process importance

Provides a structured approach for analyzing fingerprints

CODIS

Combined DNA Index System

Primary function of CODIS

To enable electronic exchange and comparison of DNA profiles

DNA profiles in CODIS from unsolved crime-scene evidence

710,000

Entities utilizing CODIS

State and local crime laboratories

Use of CODIS

Helps to solve cold cases by comparing DNA evidence

Year Gerald Wallace's body was discovered

1975

Location of Gerald Wallace's body

On his living room couch

Condition of Gerald Wallace

He had been savagely beaten, and his hands were bound

Detectives' action after discovering Gerald Wallace's body

They searched his house and cataloged evidence

Outcome of evidence collected from the crime scene

None of it led to the murderer

Outer layer of the skin

Epidermis

Layer of the skin beneath the epidermis

Dermis

Primary function of the hypodermis

To absorb shock and insulate the body

Composition of the hypodermis

Connective tissue

Function of the dermal papillae layer

Determines the form and pattern of skin ridges

Definition of a loop in fingerprint analysis

A pattern with ridges entering from one side, recurve, and exiting from the same side

Ulnar loop opening direction

Opens toward the little finger

Radial loop opening direction

Opens toward the thumb

Type lines in a loop

Two diverging ridges that surround the loop

Delta in fingerprint analysis

The triangular shaped area where type lines meet

Number of deltas a loop must have

One

Core in a loop fingerprint

The approximate center of the loop pattern

True statement in fingerprint analysis

All fingerprints have a core and delta

Fingerprint pattern characterized by ridges entering from one side, curving around, and exiting from the same side

Loop

Categorization of a loop fingerprint opening toward the thumb

Radial loop

ACE-V process steps

Analyze, Compare, Identify, Verify

Level of comparison involving general ridge flow and pattern configuration

Level 1