Transcript of "Forensic Science Topic 1. student notes "
Topic One: Introduction
What exactly is Forensic Science?
Forensic science applies the knowledge and technology of science to define and enforce
The History of Forensics
Mathieu Orfila (Spain) “Father of Forensic Science”(1787-1853)
Alphonse Bertillon (France) (1853-1914)
• Developed the science of Anthropometry – a way of taking extensive body
measurements to identify people. This technique of personal identification
was considered extremely accurate for 2 decades and was eventually replaced
Francis Galton (1822-1911)
Leone Lattes (1887-1954)
• Devised a technique to determine the blood group of a dried bloodstain and
applied the technique to criminal investigations. (The ABO blood groups
were discovered by a Dr. Karl Landsteiner in 1901)
Calvin Goddard (1891-1955)
Albert S. Osborne (1858-1946)
• Published a book “Questioned Documents”, and was responsible for the
acceptance of documents as scientific evidence by courts. Modern document
examiners still use his book as primary refernce.
Walter C. McCrone (1916-2002)
Hans Gross (1847-1915)
Last but not least…
Edmond Locard (1877-1966)
• Established “Locard’s Exchange Principle” which state that, whenever 2
objects come in contact with each other, there will be an exchange of
materials between the two.
•In 1932, thanks to J. Edgar Hoover, the director of the FBI, launched a national lab that
would offer forensic services to the entire country’s law enforcement agencies.
•Today, the FBI laboratory is the largest and most reputable in the world.
Basic Services of a Full-Service Crime Lab
Optional Services of a Full-Service Crime Lab
•Latent Fingerprint Unit
•Voiceprint Analysis Unit
Specialized Forensic Services
These are provided by specialized individuals, and are not usually a part of a full-service
Investigates sudden, unnatural, unexplained, or violent deaths. Questions a forensic
pathologist must attempt to answer:
• What injuries are present?
• What caused the injuries?
If a cause of death cannot be determined by external observation of the body, then an
Autopsy is required.
(means to see for oneself)
This a medical dissection of a body to determine cause of death. Causes of death can be
•The early stages of decomposition after death involve:
–Livor mortis: Once the heart stops pumping, the blood tends to pool in the parts of the
body closest to the ground due to gravity. The skin in these areas appear purplish.
However, skin that was restricted by belts, etc. will not appear purplish. This can help
determine if the body was moved after death. Livor mortis begins immediately after death
and continues for up to 12 hours.
–Algor mortis: this is the conditions where the body temperature cools and reaches the
ambient or room temperature. The location, size of body, clothing, weather conditions,
etc. all play a role in algor mortis.
Pallor Mortis: (paleness of death) is a postmortem paleness which happens almost
instantaneously (in the 15–120 minutes after the death) because of a lack of capillary
circulation throughout the body. Paleness develops so rapidly after death that it has little
to no use in determining the time of death.
Other Autopsy Factors
•Potassium levels in vitreous humor of eye: after death, cells of the inner eye
release potassium into the ocular fluid called vitreous humor. Examining these
levels help determine time of death.
2. Forensic Anthropology
Deals with identification and examination of human skeletal remains. Bones degrade at
an incredibly slow rate. They can tell:
• Type of injury (cause of death?)
Forensic anthropologists are often needed to identify victims of a mass disaster such as
air crashes, 9/11 WTC disaster, bombings, etc.
Ways to tell male pelvis from female:
spread of ilium:
shape of hole in ischium: smaller and triangular in female vs. larger and rounded in male
angle across pubic symphysis: pubic arch: less than 90° (acute angle) and more sharply
angled in male, greater than 90° (obtuse angle) and more rounded in female
inner diameter and distance between ischia:
•Sometimes forensic anthropologists have to use Facial Reconstruction artists to help
identify the remains.
3. Forensic Entomology
• After death, specific insects become inhabitants of the corpse in a specific
sequence. Blowflies are usually the first to arrive. Knowing the life cycles and
studying the maggots can help determine time of death. Ambient temperatures
can play a role in insect life cycles, so it can be tricky to rely solely on this
A Blowfly and its maggots
4. Forensic Psychiatry
The relationship between human behavior and legal proceedings is examined. Forensic
psychiatry can help determine:
• Suspect’s behavioral profile
• Behavioral patterns of criminals (Profiling) Susan Smith
5. Forensic Odontology
Using teeth to identify remains. Tooth enamel is the hardest substance in the
body and usually the last to decompose. So teeth can be used (and old dental
records such as X-rays and casts) to identify a body in an unrecognizable
Dental Impressions and Casts
6. Forensic Engineering