forensic science chapter 1 introduction to forensic...

1 Forensic Science Chapter 1 Notes

Forensic Science Chapter 1 Introduction to Forensic Science History and Development of Forensic Science Forensic science is the application of science to criminal and civil laws that are enforce by police agencies in a criminal justice system.

Forensic science began with those individuals who developed the principles and techniques necessary to identify or compare physical evidence, and with those who recognized the necessity of merging of those principles into a coherent discipline that practically applied to the criminal justice system.

Many believe that Sir Arthur Conan Doyle, through his fictional character, Sherlock

Holmes, popularized scientific crime detection methods. It was Holmes who first applied the principles of serology the study of blood, fingerprinting, firearm identification, and document examination long before their value was first discovered and implemented by real life criminal investigators.

The following are some pioneers who made early contributions to formulating the disciplines that now constitute forensic science: Mathieu Orfila

“Father of Modern Toxicology”

Mathieu Joseph Bonaventure Orfila (April 24, 1787 - March 12, 1853) was a French toxicologist and chemist.

Publications:

Trait des poisons or Toxicologie generate (1813)*

Elements de chimie medicate (1817)

Leons de médecine legate (1823)

Trait des exhumations juridiques (1830)

Recherches sur lempoisonnement par lacide arsenieux (1841)

His fame rests mainly on the first named work, published when he was only in his twenty seventh year. It is a vast mine of experimental observation on the symptoms of poisoning of all kinds, on the appearances which poisons leave in the dead body, on their physiological action, and on the means of detecting them.

Alphonse Bertillon

“Father of Criminal Identification”

Alphonse Bertillon was a French policeman who believed that people could be physically identified to a certainty by conducting a series of measurements. His theory was that by using 11 different measurements from a person's body, he could accurately


establish their identity at a later date. This system of identification is known as Anthropometry. Today, we use photographs and fingerprints as the standard for offender identification (booking).

Anthropometry – The areas of measurement were chosen randomly. After discarding some measurements, Bertillon decided to use the breadth of the outstretched arms, head length and width, left foot length, left little finger length, trunk height, body height, width and length of the right ear and the length of the left forearm.

Bertillon also included fingerprints as part his new system which he called "anthropometrics". Bertillon's system became popular with law enforcement during the 1880s. Offenders were measured, photographed and fingerprinted during their booking process.

However, in 1903 something happened that caused law enforcement to discard Bertillon's system of identification.

What happened to Bertillon in 1903?

In 1903, a prisoner by the name Will West was sentenced to incarceration at the United States Penitentiary at Leavenworth, Kansas.

During his in-processing, the records clerk obtained Will West's Bertillon measurements and photograph from records at the prison

Will West denied ever being incarcerated at the facility.

Subsequent investigation disclosed that a William West had previously been incarcerated in the facility until September 9, 1901.

By examining the photographs, one can see the failure of the Bertillon system.

Compare the Bertillon measurements in particular; keeping in mind the various factors that would affect the measurements. This failure strengthened the science of fingerprints as the normally accepted method of personal identification.

The authorities compared their fingerprints and determined that Will West was not the previously recorded William West.

Recent opinions suggest that Will and William West were related, therefore the closeness in measurements and appearance. As a result of this incident, Bertillon's "anthropometric" identification system was quickly discarded in favor of fingerprints.

Frances Galton

Frances Galton undertook the first definitive study of fingerprints as a method of identification.

Developed a methodology of classifying them in 1892.

His work described the basic principles that formed the present system of identification by fingerprints.

Developed a method of classification for fingerprints.

Publication: “Finger Prints” – a statistical proof of uniqueness of finger prints

Wrote the basic principles of the present system of identification by finger print analysis.

Cousin to Charles Darwin


Leone Lattes

Furthered the work of Dr Karl Landersteiner

Leone Lattes discovered that blood can be grouped into different categories. Since 1915, blood types have been recognized as A, B, AB, and O.

Developed a test to type dried blood that is used for criminal investigations.

Today, his procedure is utilized often by forensic scientists. Calvin Goddard

Ballistics – chemical analysis to tell whether a gun has been fired or not.

Use of a microscope to determine if a tool marks on a fired bullet matches a specific gun.

Established the comparison microscope as an indispensible tool of the fire arms examiner.

Albert S. Osborn

Fundamental Principles of Document Examination.

Book: Questioned Documents (still used today)

Handwriting analysis

Document examination

Paper examination Walter C. McCrone

Microscope techniques

Established the McCrone Research Institute – Chicago IL. World renown for microscope and microscope trace evidence detection.

Did analysis on the “Shroud of Turin”. Hans Gross

Wrote the first treatise on – Application of Science Disciplines to the Field of Criminal Investigation.

Book – Criminal Investigation: use of microscope, chemistry, mineralogy, zoology, botany, and anthropometry.

Forensic Journal – to report new and improved methods of scientific crime detection. Dr. Edmond Locard

Established the first workable crime lab.

Founder and Director of the Institute of Criminalistics at the University of Lyons. International Center for the study and research in forensic science.

Wrote: Locards Exchange Principle

Locards Exchange Principle


o States and believes that every criminal can be connected to a crime scene by dust particles carried to the crime scene, transfer occurs whenever a criminal comes into contact with objects or a person.

The Forensic Laboratory

J. Edgar Hoover and the FBI in 1932 organized a national laboratory to offer forensic services to all law enforcement agencies in the country.

This lab is now the world’s largest forensic lab, performing over a million examinations per year

Quantico - FBI Forensic Science Research and Training Center (c1981) o Used as a model for forensics labs formed at the state and local levels in the US

and other countries.

LAPD o The oldest crime lab in the US. o Created by August Vollmer in 1923. o In 1930’s Vollmer headed the first US University Institute for Criminology and

Criminalistics at UC Berkley. o California was also the first state to network all the labs and share information.

United Kingdom Lab o In the United Kingdom, forensic laboratories charge for their services as a means

of funding. o It is thought that there is an increase in accountability and efficiency.

Organization of a Crime Lab

1. Federal Level: FBI Federal Bureau of Investigation DEA Drug Enforcement Agency ATF Alcohol Tobacco and Firearms USPS United States Postal Service

2. State Agencies – each state has at least one forensic lab. Some states have a statewide network, while others use a regional system.

3. Private Forensics Labs - there are about 320 private laboratories. 4. Municipal – these are usually independent of the state labs. Example NYC has a

forensic lab, specifically for the five boroughs of NYC. 5. Other Countries - Approximately 100 nations have at least one forensic

laboratory.

Canada – Has three laboratories as well as six Royal Mounted Police laboratories.

Two training facilities: o Center for Forensic Sciences – Toronto o Inst. of Legal Medicine and Forensic Sciences – Montreal


Services of the Crime Lab There are a wide variety of services available, the services offered varies from lab to lab. This is due to:

a. Variations on the laws b. Different capabilities and functions of the organization heading up the lab. (ex:

DEA vs. FBI) c. Budgeting and staffing limitations.

“Full Service” Laboratory Services

1. Physical Science Unit – applies physics, chemistry, geology to the identification and comparison of crime scene evidence. (drugs, glass, paint, explosives and soil)

2. Biology Unit – biologists and biochemists apply their knowledge to analysis of DNA, dried blood and other body fluids, comparison of hair and fibers.

3. Firearms Unit (Ballistics) – examination of: discharged bullets, casings, shot gun shells and ammunition; Garments and other items for gun powder residue; distance between the firearm and the target; comparison of tool marks on bullets and guns.

4. Document Examinations Unit – comparison and examination of: handwriting, typewriting, ink, toner, paper, charred documents and/or erasures/obliterations.

5. Photography Unit – responsible for: a. Examination and photographic record of the crime scene. b. Digital imaging and enhancement via UV and x-ray photography. c. Preparation of photographic exhibits for court.

Optional Service

1. Toxicology – presence of drugs or poisons in the body fluids or tissues. 2. Latent Finger Prints Unit – responsible for processing and examining evidence for

fingerprints. 3. Polygraph Unit – (lie detector test) can be offered at either the forensic lab or the police

station. 4. Voice Print Analysis – examination of recorded evidence.

a. This procedure may be able to identify the voice to a particular suspect. b. Spectrograph – transforms speech into a visible graphic display (voice print)

5. Evidence Collection Unit – specially trained personnel whose primary function is to recognize, collect and preserve physical evidence at the crime scene.

Functions of the Forensic Scientist Analysis of Physical Evidence: any procedure used to analyze physical evidence must satisfy the criteria of admissibility that has been established by the courts. Precedent Cases:

1. Frye standard – the court decides if a procedure is: a. generally accepted b. Accepted and considered relevant by the scientific community.

2. Federal Rules of Evidence (rule 702)


a. Testimony is based on facts or data. b. Is a product of reliable principles and methods. c. Applies the principles and methods to the facts of the case. d. Rule 702 is applicable to state courts if:

i. The scientific technique or theory can be and has been tested. ii. If the technique/theory has been subject to peer review and publication.

iii. The techniques potential rate of error is low. iv. Existence and maintenance of standards controlling the techniques

operation. v. Whether the scientific theory/method has attracted widespread

acceptance within the relevant scientific community. Provision of Expert Testimony

Forensic scientist – may be called upon to testify regarding the methods and conclusions at a trial hearing.

To be considered an expert witness: o The witness must provide his or her background: training, educational degrees,

relevant experience, professional societies, and publication of articles and papers.

o This all determines the competency of the witness. o The expert’s credentials are on trial to allow the witness to give their

professional opinion. Any testimony given is opinion, based on a reasonable certainty based on

training and experience. Expert witness is expected to defend the tests in question.

Evidence Collection Unit

Personnel are specially trained to recognize, collect and preserve physical evidence.

These technicians retrieve evidence from the crime scene. Forensic Pathologist (Medical Examiner or Coroner)

This person is a medical doctor. o Responsibilities:

Autopsy – method of dissection to determine the cause of death. 5 categories of death: Natural, Accidental, Suicide, Homicide and

Undetermined. Determination of the time of death:

The stages of decomposition are used to determine the approximate time of death. 1. Rigor mortis- immediately upon death the muscles relax, soon after they stiffen

causing the body to become rigid. (Lasts from 24-36 hours). 2. Livor Mortis – occurs when the blood settles to the lowest point, based on body

position. This causes the tissues in that area to appear blue/black to purple.


a. Areas that were during constricted during the livor mortis period appear pale or bloodless.

3. Algor mortis - is the cooling of the body after death. a. Time of death can be calculated using the ambient room temperature and

the rate of heat loss from the body. b. Factors include: "size" of the body, clothing and coverings, movement and

humidity of the air, and immersion in water. “Under average conditions the clothed body will cool in air at the rate of about 1.5°C an hour for the first 6 hours and average a loss of some 1°C for the first 12 hours."

c. This method is used to approximate time of death. Forensic Anthropologist

Forensic anthropology is the application of physical or biological anthropology in a legal context.

The majority of cases encountered by a forensic anthropologist involve the human skeleton.

The routine activities of the forensic anthropologist extend to the examination of badly decomposed or severely damaged human bodies.

Forensic anthropologists are also called on in the search and recovery of human remains.

o Through forensic anthropology the following may be identified using the skeletal remains: Origin, sex of the victim, approximate age, race, height and possible skeletal injuries or identifiers.

Forensic Entomology

Is the use of the insects, and their arthropod relatives that inhabit decomposing remains to aid legal investigations.

Often insects can aid in determining the time of death. Insects can often be useful evidence for toxicologists to identify toxic substances from

the remains. Forensic Psychiatry

Studies the relationship between human behavior and legal proceedings. Evaluation of the competency of the accused. Study of behavioral patterns – criminal behavior profile.

Forensic Odontology Is a doctor trained in dentistry with additional training in forensic dentistry. Provide information about the identity of a victim when the body cannot be identified. Match the characteristics and alignment of teeth to a bite mark.