Pattern Evidence and Locard's Principle Exam Study Guide Flashcards
Forensic Science
relating to or dealing with the application of scientific knowledge to legal problems
Crimininalistics
the application of forensic science to criminal matters
Criminology
social science study of crime and criminal behavior
Locard’s Principle
is the principle that every time someone enters an environment, something is added to and removed from it
What does Locard’s Prinicple mean for science?
it improved science and it provides us with valuable information as to the circumstances of a crime scene
Physical Evidence
tangible articles
Inceptive Evidence
evidence used to show whether or not a crime has been committed
Examples of Inceptive Evidence
seized blocks of cocaine
Identification Evidence
used to identify someone
Associative Evidence
associates someone with the scene
Examples of Identification Evidence
fingerprints, DNA testing, firearms, etc.
Corroborative Evidence
used to support other evidence
Examples of Associative Evidence
weapons, hair, fibers, etc.
Scene Processing
the scientific method of gathering evidence from a crime scene
Crime Scene
a place where a crime was committed
Why is it important to know how a perpetrator entered and excited the crime scene ?
it is important because it can tell you how to document a crime scene and give you better clues on to what happened at the scene
Chain of Custody
every item removed from the scene and taken to the laboratory must be identified in a way that guarantees its integrity
Why is it important to maintain chain of custody?
chain of custody is so important because it assures to the court and anybody else that the evidence is authentic
Entry
how the scene was entered
Egress
exiting the scene
Where do most forensic scientist work?
in crime labs
Where else can forensic scientists work?
crime scene clean up, analysis worker, etc.
Pattern Evidence
any markings produced when one object comes into contact with another object
Class Characteristics
identifying trait shared by a group of similar objects
Examples of Class Characteristics
identical tread patterns, same spacing of grooves/ridges, etc.
Individual Characteristics
identifying trait unique to a specific object
Examples of Individual Characteristics
imperfections, wear and tear, and embedded foreign objects
How can you use class characteristics at a crime scene?
to narrow down the list of possible sources
How can you use individual characteristics at a crime scene?
you can compare them to an exemplar
Exemplar
a known sample
What is an exemplar used for?
used to be compared with objects from a crime scene to make a conclusion
Striations
lines made by surface imperfections
How can you see striations?
with the eye or under microscope
Identification Evidence Interpretation
sufficient data to match a pattern with a person or object
Inconclusive Evidence Interpretation
not enough data to identify or exclude person/object
Exclusion Evidence Interpretation
find sufficient differences between the known and the evidence to exclude person or object
Macroscopic Examination
visible to the naked eye
Microscopic Examination
requires the use of a microscope in order to view
What can you learn from tire impressions?
- which vehicle
- what direction
- where the vehicle went
- how fast the vehicle was going
Wheelbase
front to back
Track Width
right to left
Examples of Corrobarative Evidence
photographs and videos
