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
study 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 – study 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 – study titled 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 Optional 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.