Chapter 1 - Introduction

Basics of Forensic Science

Definition and Scope Forensic science is the application of

science to law: Applies the knowledge and

technology of science to the definition and enforcement of laws

Laws are continually being broadened and revised to address the alarming increase in crime rates

The Role of Science Science cannot offer final and

authoritative solutions to all problems

Social and psychological factors are always present

Science plays an important and unique role in the criminal justice system – ability to supply accurate and objective information that reflects events that have occurred at a crime scene

Definition of Forensics Science

The application of science to the to the criminal and civil laws that are enforced by police agencies in a criminal justice system.

Diversity of Professions Involved According to the American Academy of Forensic

Science: Criminalistics (synonym for forensic science) Engineering Science General Jurisprudence Odontology Pathology/Biology Physical Anthropology Psychiatry/Behavioral Science Questioned Documents Toxicology

Additions to the list of 10:

Fingerprint examination Firearm and tool mark

examination Technology analysis

Computers Digital data analysis

Photography

History and Development Individuals who developed the

principles and techniques needed to identify or compare physical evidence

Those who recognized the need to merge these principles into a coherent discipline that could be practically applied to a criminal justice system

Early Developments One of the earliest records:

3rd century China – manuscript Yi Yu Ji Case solved where a woman was suspected

of murdering her husband Evidence showed that he was murdered

and she admitted her guilt Chinese were also the first to recognize the

potential of fingerprints for identification purposes

Often the exception rather than the rule for criminal investigations

Early Developments (continued…)

Limited knowledge of anatomy and pathology Hampered the development of

Forensic Science until late 17th and early 18th centuries

First recorded notes about fingerprint characteristics 1686, Marcello Malpighi Did not acknowledge the value of

fingerprints as a method of ID

Initial Scientific Advances

1798; “A Treatise on Forensic medicine and Public Health” François-Emanuel Fodéré

Breakthroughs in chemistry also helped 1775; Carl Wilhelm Scheele devised

first successful test for detecting arsenic in dead bodies

Initial Advances (continued…) 1814; Mathieu Orfila

Father of forensic toxicology Published the first scientific treatise

(study) on the detection of poisons and their effects on animals

Mid-1800s Advance of several scientific disciplines

which advanced the field of forensics 1828; William Nichol – polarizing microscope 1839; Henri-Louis Bayard – microscopic detection of sperm 1839; toxicological evidence first used at a trial 1853; microcrystalline test for hemoglobin 1863; first presumptive test for blood 1850s and 1860s; use of photography in forensics

Late 19th-Century Progress Beginning to apply knowledge from all

scientific disciplines to the study of crime

Anthropology/Morphology (structures of living organisms) applied to the first system of personal identification 1879; Alphonse Bertillon Named anthropometry – systematic

procedure for using a series of body measurements as a means of distinguishing one person from another (later replaced by fingerprinting)

Father of Criminal Investigation

More on the 19th century…

Bertillon’s anthropometry later replaced by fingerprinting Thomas Taylor (American) said that

fingerprints could be used for ID Supported by Scottish physician

Henry Faulds 1892; Francis Henry Gaulton

undertook the first definitive study of fingerprints and developed a method for classifying them

Sherlock Holmes Not a real person Legendary but fictional detective in

stories by Sir Arthur Conan Doyle Had a considerable influence on

popularizing crime-detection methods Applied newly developing principles of

serology (blood/body fluids), fingerprinting, firearms ID and document analysis in his stories

Doyle’s “A Study in Scarlet” is a classic example (see excerpt)

20th Century Breakthroughs 1901; Karl Landsteiner

Discovered ABO blood types 1910; Albert S. Osborne

Wrote the first significant text on Questioned Documents (document examination)

1915; Dr. Leon Lattes Developed a simple procedure for identifying

the blood group from a dried blood stain Immediately applied to criminal investigations Acceptance of documents as scientific evidence

by the courts 1923; Calvin Godddard

Used comparison microscope to refine techniques of firearms examination

Edmond Locard French Formal education in both medicine and law Started the first police lab in 1910 Founder and director of the Institute of

Criminalistics @ the University of Lyons (France) Leading international center for study and

research in forensic science Strongly believed every criminal can be

connected to a crime by dust particles carried from the crime scene

Locard’s successes helped start police labs in Vienna, Berlin, Sweden, Finland and Holland

Locard’s Exchange Principle

When two objects (or people) come in contact with each other, a cross-transfer of materials occurs

Modern Scientific Advances

Mid-20th century Revolution in computer technology Dramatically impacted the field of forensics Wide array of sophisticated techniques for

analyzing evidence available Chromatography Spectrophotometry (measuring the

absorption/reflection of light by materials) Electrophoresis

DNA Most significant modern advance DNA typing and profiling 1984; Sir Alec Jeffries developed the

first DNA profiling test 1986; DNA profiling used to solve the

“Pitchfork” murders of two young English girls (Colin Pitchfork)

Precise ID of a suspect can be determined

Computer Databases

Fingerprints Bullets and shell casings DNA

Significantly reduced the time it takes to analyze evidence and increase accuracy of the results

Key Points: Forensic science is the application of science to

criminal and civil laws that are enforced by police agencies in a criminal justice system

The first system of criminal ID was called anthropometry. It distinguished one individual from another based on a series of body measurements

Forensic science owes its origins to individuals such as Bertillon, Gaulton, Lattes, Goddard, Osborne and Locard, who developed the techniques needed to identify or compare physical evidence.

Locard’s Exchange Principle states that when two objects come in contact with each other, a cross-transfer of materials occurs that can connect a criminal suspect to his/her victim.

Crime Laboratories - History 1923; Los Angeles Police Dept. crime lab is the

oldest Established by August Vollmer

1948; School of Criminology formed at UC-Berkley

1932; FBI established under President Herbert Hoover Offered forensic services to all law enforcement

agencies in the USA 1981; Forensic Science research and Training

Center for research and development of new techniques/tools/methods

Train lab personnel in the latest techniques Most labs are run locally or at the state level

Organization of a Crime Lab Characterized by rapid growth Lack of national/regional

planning/coordination Levels: federal, state, county,

municipal Size and diversity makes it impossible

to adopt a single model of operation Most function as part of the local

police department, prosecutor, district attorney or medical examiner (coroner)

Growth Several reasons explain the rapid

growth of crime labs in the past 40 years Supreme Court decisions requiring

scientific, objective treatment of evidence Constitutional rights of suspects (Miranda

Rights) Changing judicial requirements due to the

staggering increase in crime rates in the USA, especially drug-related crime

DNA technology/profiling needs more qualified personnel to analyze the evidence

Drug cases still outnumber DNA cases

Crime Labs in the USA

Desire to retain local control Produced a variety of

independent labs Government has no single law

enforcement agency with unlimited jurisdiction

Crime Labs in the USA (continued)

1. FBI (Department of Justice) Maintains the largest crime lab in the world Ultramodern facility located in Quantico, VA

2. DEA (Drug Enforcement Administration - (Department of Justice)

Analyzes drugs seized in violation of federal laws regulating production, sale and transport

3. ATF (Alcohol, Tobacco and Firearms) Analyzes alcoholic beverages Examines documents related to alcohol and firearm excise tax

law enforcement Examines weapons, explosive devices and related evidence

Gun control Act of 1968 Organized crime Control Act of 1970

4. U.S. Postal Service Criminal investigations related to the postal service

Local and International Crime Labs Most state governments maintain a

crime lab some wit regional or satellite offices (larger states) Try to be cost-effective by not duplicating

services Most countries have created and

maintain facilities Organization can vary from country to

country Often operate on a fee-for-service basis

(some can be private companies)

Services of the Crime Lab Wide variation in total services

offered There are many reasons for this

Variations in local laws Different capabilities/functions of the

organization to which the lab is attached

Budgetary and staffing limitations (often very limited)

Some labs have strict functions like processing drug specimens only

Basic Services Physical Science Unit

Principles of chemistry, physics and geology ID/comparison of crime-scene evidence

Biology Unit Biologists/biochemists DNA profiling, ID/comparison of biological evidence including

botanical materials Firearms Unit

Examines firearms, discharged bullets, cartridge cases, shotgun shells, ammunition, residues, tool marks

Determine composition, distance, angles Document Examination Unit

Handwriting/typewriting on questioned documents Ascertain authenticity/source

Photography Unit Examines/records photographic evidence Uses highly specialized techniques such as digital imaging, IR,

UV, X-ray to make invisible images/information visible

Optional Services Provided by a Full-service Crime Lab

Toxicology Unit Examines body fluids/organs to determine the

presence/absence of drugs Latent Fingerprint Unit

Processes and examines fingerprint evidence Polygraph Unit

Lie detecting Voiceprint Analysis Unit

Involves cases of telephone threats or recorded messages

Trained analysts tie the voice to a suspect Sound spectrograph creates a voiceprint Sound patterns produced in speech are unique

Optional Services (continued) Crime-Scene Investigation Unit

Dispatched specially trained personnel to a crime scene to collect/preserve evidence to be analyzed later in the lab Includes forensic pathology, entomology and anthropology

Forensic Psychiatry Examines the relationship between human behavior and legal

proceedings Behavior patterns of criminals/behavior profile

Forensic Odontology ID victims based on dental evidence Bite mark analysis linked to tooth structure on a suspect

Forensic Engineering Failure analysis, accident reconstruction, causes/origins of

fires/explosions Forensic Computer/Digital Analysis

Identifying, collecting, preserving and examining information derived from computers/digital devices

Key Points: The development of crime labs in the USA has been characterized

by rapid growth accompanied by a lack of national and regional planning and coordination

Four major reasons for the increase in the number of crime labs in the USA since the 1960s are as follows:1. The fact that the requirement to advise criminal suspects of their

constitutional rights, right to immediate access to counsel has all but eliminated confessions as a routine investigative tool;

2. The staggering increase in crime rates in the USA3. The fact that all illicit drug seizures must be sent to a lab for

confirmatory chemical analysis before a case can go to court;4. The advent of DNA profiling

The technical support provided by crime labs can be assigned to 5 basic services:

Some crime labs offer optional services such as toxicology, fingerprint analysis, polygraph administration, voiceprint analysis, and crime-scene investigation.

Special forensic services available to the law enforcement community include forensic pathology, entomology, psychiatry, odontology, engineering, computer/digital analysis.

Functions of the Forensic Scientist

Analyzing Physical Evidence Apply principles of physical/natural

sciences in analyzing evidence Only physical evidence is free of

error/bias Must undergo scientific inquiry – the

integrity of evidence comes from applying the scientific method Not tainted by human error/distortion

of facts

Functions of the Forensic Scientist (continued)

Determining the admissibility of evidence Frye vs. The United States

Procedures/techniques/principles are “generally accepted” by the scientific community

Federal Rules of Evidence Governs admissibility of evidence including

expert testimony on a scientific/technical matter if:1. Testimony is based on sufficient facts/data2. Testimony is the product of reliable

principles/methods3. Witness has applied the principles/methods

reliably to the facts of the case(also used in state courts)

Functions of the Forensic Scientist (continued)

Judging Scientific Evidence Judge assumes ultimate responsibility for

admissibility/reliability of evidence The Court offers some guidelines

1. Whether the scientific technique/theory can be tested2. Whether the scientific technique/theory has been subject of

peer review/publication3. Technique’s potential rate of error4. Existence/maintenance of standards controlling the technique’s

operation5. Whether the scientific technique/method has attracted

widespread acceptance within the relevant scientific community

Providing Expert Testimony Performing the analysis of evidence May be required to testify in court about their methods, etc. Education/training is very important

Key Points: A forensic scientist must be skilled in applying

the principles and techniques of the physical/natural sciences to analyzing evidence that may be recovered during a criminal investigation.

The cases Frye vs. the United States and Daubert vs. Merrell Dow Pharmaceuticals, Inc. set guidelines for determining the admissibility of scientific evidence into the courtroom.

An expert witness evaluates evidence based on specialized training/experience.

Forensic scientists participate in training law enforcement personnel in the proper recognition, collection and preservation of physical evidence.