FOR10002 Final: Introduction to Forensic Science FOR10002 - SEMESTER NOTES
FORENSIC SCIENCE FOR10002
SEMESTER NOTES
INTRODUCTION
Definitions
Forensic: Relating to, used in, or appropriate for courts of law or for public discussion or
argumentation.!
Science: The investigation of natural phenomena through observation, theoretical explanation,
and experimentation, or the knowledge produced by such investigation !
Forensic science: The application of scientific knowledge and methodology to legal problems
and criminal investigations.!
Increasingly, scientists are being asked to provide evidence that is considered admissible in the
judicial system, hence forensic science physical evidence of criminal activity Investigation of
crime.!
!
The evidence should prove both: !
•That a crime was committed!
•That a named person or persons are responsible for committing the crime!
Conclusions have to be substantiated to a certain level of penalties for criminal cases to result in
loss of freedom penalties, for civil cases generally involve compensation.!
In criminal cases, the prosecution has to provide evidence that is “beyond reasonable doubt” !
•It is far worse to convict an innocent person than to let a guilty person go free — statistics
are important !
In civil cases, one side has to demonstrate that a “preponderance of the evidence” favours their
argument !
•More evidence in its favour than against.!
Forms of Evidence
•Direct evidence – doesn’t require inference (eg. - An eye witness that observes a crime) !
•Indirect or circumstantial evidence – based on inference (eg. - An eye witness sees someone
fleeing from a crime scene but doesn’t actually see the criminal act)!
•Negative evidence – when a usual event doesn’t occur (eg. - Guard dog doesn’t bark during a
burglary).!
Forensic science is generally applied to develop circumstantial evidence to create inference!
Forensic Science
Forensic science is often thought to be used to solve only cases of serious crime, such as
homicide, sexual assault, burglary, theft, arson = relatively low frequency of occurrence.!
Approximately 50% of all work carried out in forensic laboratories is concerned with drink/driving
offences and 20% is concerned with drug offences.!
Key Concepts
PRECEDENT RULES
Precedent rules refers to whether a scientific method can be used in the legal system!
Why?
•Proving a new technique is expensive - does the technique provide an accurate result? !
•Validating a new technique is even more expensive - can the technique be widely
implemented?!
Timeline
•1591 Microscopy - Zacharias and Hans Jansen design the first microscope!
!
•1721 Photography - A German physician, Johan Heinrich Shulze, demonstrates the ability to
leave an image on a solution of chalk and silver nitrate In !
•1822 Photography - Louis Daguerre developed a reliable photographic process. !
•1804 Physics - J.W. Ritter discovers ultraviolet rays that enabled erased writing and blemishes
to be detected!
•1814 Toxicology - Mathieu Orfila publishes the text Traité de Poisons, a method for classifying
poisons !
•1835 Ballistics - Henry Goddard begins to make comparisons between casting flaws on a
bullet with bullet molds !
Go to http://www.firearmsid.com/A_historyoffirearmsID.htm for a more complete history !
•1836 Toxicology - Alfred Swaine Taylor publishes Elements of Medical Jurisprudence. James
Marsh develops a test for detecting small amounts of arsenic in human tissue!
•1850 Spectroscopy - Bunsen and Kirchoff discover that gas fumes give off light and energy
according to their atomic structure when subjected to fluctuating temperature !
•1858 Fingerprints - Sir William Herschel introduced the concept that fingerprints were unique
to each person !
Go to http://onin.com/fp/fphistory.html for a more complete history !
•1875 X-rays - Professor Wilhelm Konrad Röntgen discovers that solid objects when placed in
the path of cathode rays produce secondary radiation which delineates the shapes of solid
matter!
•1882 Anthropometry - Alphones Bertillon develops a criminal classification system based on
body measurements Bertillon's system included measurements such as head length, head
width, length of the middle finger, length of the left foot, and length of the forearm from the
elbow to the tip of the middle finger!
•1893 Criminalistics - Hans Gross publishes his text Hanbuch für Untersuchungsrichter als
System der Kriminalistik on the scientific investigation of crime !
•1901 Serology - Karl Landsteiner develops the first system of blood grouping, known as the
“ABO System” Paul Uhlenhuth uses protein composition to enable human blood to be
distinguished from other animal blood !
•1912 Ballistics - Victor Balthazard improves the technique of comparing bullets from the scene
of a crime with those from a suspect gun by using photographic enlargements!
