Exam 1 Flashcards
The Scientific Process
- Observation
- Ask Question
- Hypothesis/Prediction
- Experiment(s)
- Analysis of Results
- Conclusion
Paradigm
Tested and researched so much that it now is a
foundational concept for understanding systems
Theory
Highest level of knowledge in science. Based on hypotheses that withstood multiple, rigorous testing without being disproven
Hypothesis
A possible explanation for a set of observations. Not a random guess or opinion and is testable.
Deductive Reasoning
Applies general principles to reach specific conclusions.
Inductive
Assimilates specific information
to build general principle.
Deduction in Forensic Science
When someone fires a gun, GSR
is deposited on hand,
GSR contains nitrates,
Suspect X tested for GSR
positive, Deduction: Suspect X recently discharged a firearm. If the premise is true, the
conclusion must be true.
Archimedes
Father of Forensic Science. Calculated Density
(water displacement).
Hans Gross
- Created field of Criminalistics
- Criminal Investigation 1891
- Handbook on Forensic Science
Anthropometry
The study of Body Measurements.
Density
= Mass/Volume
We can measure volume
then calculate density
Alphonse Bertillon
Body Measurements. “Father of criminal identification.”
Sir Frances
Galton
- 1892: the lexeme “fingerprint”
- First definitive study &
classification of fingerprints - 1903: used in US for criminal ID
The Marsh Test
Mix suspected fluid (has arsenic)
with sulfuric acid & zinc
↓
Arsine gas is formed
↓
Gas heated & condenses on cold
surface as silvery black deposit.
James Marsh
Create Marsh test in 1886.
- Highly sensitive
- Detects even trace amounts
- Visible proof
Toxicology
Foundations in 1800s alongside developments in medicine and pathology.
started with Arsenic poisoning.
Karl Landsteiner
- In 1900 founded ABO blood groups
- Won Nobel Prize (1930)
- Serology
Leone Latte
- 1915
- First blood typing test
- Dried blood stain
Edmund Locard (trace evidence)
1877-1966
- “Every contact leaves a trace”
- Significance of physical evidence
- Basis of forensic microscopy
* Founded first crime lab in
Lyon, France 1910
Locard’s Exchange Principle
Wherever he steps, whatever he touches,
whatever he leaves, even unconsciously, will serve
as a silent witness against him.
Not only his fingerprints or his footprints, but his
hair, the fibers from his clothes, the glass he
breaks, the tool mark he leaves, the paint he
scratches, the blood or semen he deposits or
collects.
All of these and more, bear mute witness against
him….
Locard’s Exchange breakdown
This is evidence that does not forget. It is
not confused by the excitement of the
moment. It is not absent because human
witnesses are.
It is factual evidence.
Physical evidence cannot be wrong, it
cannot perjure itself, it cannot be wholly
absent.
Only human failure to find it, study and
understand it, can diminish its value.”
Matheiu Orfila
- “father of forensic toxicology”
- 1814 scientific treatise on
detection of poisons and their
effects on animals
- 1814 scientific treatise on
1840 Marie Lafarge trial
- Marsh Test used
- Landmark case
- 1st use of science in court
conviction