This document provides an overview of forensic science. It discusses how forensic science applies various sciences like chemistry, biology, and physics to civil and criminal law. It traces the development of forensic science from figures like Sir Arthur Conan Doyle in the late 1800s and describes the services provided by modern crime labs, including units for physical science, biology, firearms examination, and toxicology. It outlines the functions of forensic scientists in analyzing evidence and providing expert testimony.

1. An Introduction to
Forensic Science

2. What is Forensic Science?
□ …the application of science to those
criminal and civil laws that are enforced by
police agencies in a criminal justice
system.

3. Forensic Science is…
□ Applied Science
□ Often called “criminalistics”

4. Forensic Science applies
□ Chemistry
□ Biology
□ Physics
□ Geology
Places physical evidence into a professional
discipline.
to civil and criminal law
}

5. The development of
Forensic Science

6. Sir Arthur Conan Doyle
□ Popularized physical detection
methods in a crime scene
□ Developed the character Sherlock
Holmes

7. Sir Arthur Conan Doyle
□ 1887 published first novel, A Study in Scarlet
□ "I've found it! I've found it," he shouted to my companion, running towards
us with a test-tube in his hand. "I have found a re-agent which is
precipitated by haemoglobin, and by nothing else . . . . Why, man, it is the
most practical medico-legal discovery for years. Don't you see that it gives
us an infallible test for blood stains? . . . . The old guaiacum test was very
clumsy and uncertain. So is the microscopic examination for blood
corpuscles. The latter is valueless if the stains are a few hours old. Now,
this appears to act as well whether the blood is old or new. Had this test
been invented, there are hundreds of men now walking the earth who would
long ago have paid the penalty of their crimes. . . . Criminal cases are
continually hinging upon that one point. A man is suspected of a crime
months perhaps after it has been committed. His linen or clothes are
examined and brownish stains discovered upon them. Are they blood
stains, or mud stains, or rust stains, or fruit stains, or what are they? That is
a question which has puzzled many an expert, and why? Because there
was no reliable test. Now we have the Sherlock Holmes's test, and there will
no longer be any difficulty."
→ had a considerable influence on popularizing scientific crime-detection methods

8. Mathieu Orfila (1787 – 1853)
□ Father of Forensic Toxicology
□ 1814 - Treatise on detection of poisons
& their effects on animals.

9. Alphonse Bertillon (1853 – 1914)
□ Father of Criminal Detection
□ Devised the first scientific system
of personal identification, using
body measurements known as
anthropometry in 1879.

10. Francis Galton (1822 – 1911)
□ Conducted the first definitive study of
fingerprints and their classification.
□ 1892 – Treatise entitled Finger Prints

11. Leone Lattes (1887 – 1954)
□ Devised a simple procedure for
determining the blood type (A,B,O,AB) of a
dried bloodstain

12. Calvin Goddard (1891 – 1955)
□ Used a comparison microscope to
determine if a bullet was fired from a
specific gun
□ Published study of “tool marks” on bullets

13. Albert S. Osborn (1858 – 1946)
□ Developed fundamental principles of
document examination
□ 1910 – Treatise Questioned Documents
□ Was responsible for the acceptance of
documents as scientific evidence by the
courts

14. Edmond Locard (1877 – 1966)
□ Demonstrated how the principles
developed by Hans Gross could be
incorporated into a workable crime
lab.
□ Locard's exchange principle states
that once contact is made between
two surfaces a transfer of material(s)
will occur.

15. Organization of a
Crime Laboratory

16. Crime Labs
□ Since the 1960's the number of crime labs
increased due to the courts demanding
secure scientifically evaluated evidence.
□ More crime
□ More drug related crime
□ Greater need for physical evidence
□ Use of DNA profiling (1990’s)
Presently there are 350 Crime Laboratories in the U.S.

17. Services of the Crime Lab
□ Many local crime laboratories have been created
solely for the purpose of processing evidence
□ Currently most of their energy and funds are used to
analyze drugs and DNA.
□ In 1932, Hoover first established a national
forensics laboratory to support all law
enforcement in the U.S.
□ The oldest American forensics laboratory is in
Los Angeles, California, created in 1923 by
August Volmer.

18. Crime Lab Units
Standard
Physical Science
Biology
Firearms
Documents
Photography
Optional
Toxicology
Fingerprints
Polygraph
Voice Print
Evidence

19. Basic Services Provided by
Full-Service Crime Laboratories
□ Physical Science Unit:
□ Applies the principles and techniques of
Chemistry
Physics
Geology
to the identification and comparison of crime-
scene evidence
□ Biology Unit:
□ Identifies dried bloodstains and body fluids
□ Compares hairs and fibers
□ Identifes and compares botanical materials such as
wood and plants
□ Performs DNA analysis

20. Basic Services (continued)
□ Firearms Unit: examines
□ Firearms
□ Discharged bullets
□ Cartridge cases
□ Shotgun shells
□ Ammunition of all types
□ Document Examination Unit:
□ Analyzes handwriting, paper and printers of
documents
□ Photography Unit:
□ Examines and records physical evidence at the crime
scene and at suspects' locations

21. Optional Services Provided by Full-
Service Crime Labs
□ Toxicology Unit:
□ Examines body fluids and organs in order to
determine the presence and identification of drugs
and poisons
□ Latent Fingerprint Unit:
□ Processes and examines evidence for latent
fingerprints
□ i.e. those found on surfaces
□ Polygraph Unit:
□ Uses lie detectors, an essential tool of the crime
investigator rather than the forensic scientist

22. Optional Services (continued)
□ Voiceprint Analysis Unit:
□ Involved in cases of telephone threats or
tape-recorded messages
□ Investigators may be able to connect a voice
to a particular suspect
□ Evidence-Collection Unit:
□ Incorporates evidence collection into a total
forensic science service

23. The Functions of the
Forensic Scientist
□ Analysis of Physical Evidence
□ The forensic scientist must be skilled in applying the
principles and techniques of the physical and natural
sciences in order to identify the many types of
evidence that may be recovered during crime
investigations.
□ Expert witness
□ An expert witness possesses a particular skill or has
knowledge in a trade or profession that will aid the
court in determining the truth.

24. The Functions of the
Forensic Scientist
(continued)
□ Specially trained evidence collection
technicians
□ Training in Proper Recognition,
Collection, and Preservation of
Evidence is required so that
the forensic pathologist, as the
medical examiner or coroner,
can determine the cause of
death via an autopsy.

25. Other Forensic Services
Death can be classified into five different categories:
natural death, homicide, suicide, accident or
undetermined manner of death.
□ Forensic Pathology
□ The cause of death can
often be determined by
performing an autopsy

26. Other Forensic Services - 2
□ Forensic Pathology – continued
□ After a human body expires there are several stages
of death
□ Rigor Mortis
□ immediately following death, the muscles relax and then
become rigid, shortening of the muscles.
□ Livor Mortis
□ when the human heart stops pumping, due to the blood begins
to settle in the parts of the body closest to the ground due to
gravity. The skin will appear dark blue or purple in these lower
areas close to the ground.
□ Algor Mortis
□ the process in which the body temperature continually cools
after death until it reaches room temperature, enabling the
medical examiner to establish the general time of death.

27. Other Forensic Services - 3
□ Forensic Anthropology:
□ Primarily involves the identification and
examination of skeletal remains, in order to
determine if the remains are human or
another type of animal.
□ If human, ethnicity, sex, approximate age, and
manner of death can often be determined by
an anthropologist.

28. Other Forensic Services - 4
□ Forensic Entomology
□ The study of insects and their developmental
stages
□ Can help to determine the time of death by
knowing when those stages normally appear
in the insect's life cycle

29. Other Forensic Services - 5
□ Forensic Psychiatry
□ The study of human behavior and legal
proceedings in both civil and criminal cases
□ In civil and criminal cases, competency often
needs to be determined
□ In criminal trials, the evaluation of behavior
disorders is often required in order to
establish the psychological profile of a
suspect.

30. Other Forensic Services - 6
□ Forensic Odontology
□ An odontologist can match bite marks to a
suspect's teeth, or match a victim to his dental
x-rays
□ Results in an identification of an unknown
individual
□ Forensic Engineering
□ Used to analyze construction accidents, and
the causes and origins of fires or explosions

31. Forensic Analysis
□ Can include organic and inorganic
analytical techniques
□ Organic analysis of unknown substances
□Includes analytical techniques such as
Chromatography, UV- visible and infrared
Spectrophotometry and Mass Spectrometry.
□ Inorganic analysis
□Includes techniques such as the emission
spectrum of elements, Atomic Absorption
Spectrophotometry, Neutron Activation Analysis,
and X-Ray Diffraction Analysis.