CSI Midterm Flashcards
What is the purpose of crime scene investigation?
to document the scene context and recover any evidence in order to prove or disprove a case
Definition of evidence
anything that tends to prove or disprove a fact in contention
class evidence/characteristics
a trait characteristic that allows the item to be compared with another group of items and included or excluded in the group
individual evidence/characteristics
trait or characteristic that allows the item to be compared to an individual item or person
What is cross contamination? How can it be prevented?
transfer of bacteria or other microorganisms from one substance to another
this can be prevented by wearing gloves, tying hair back, not moving anything
What is Nuclear DNA?
individual evidence
essential for copying and passing genetic information to the next generation
What is Mitochondrial DNA?
present in greater number in every cell, DNA shared in a family
What are examples of crime scene integrity issues?
addition of material to the scene, destruction of material in the scene, movement of material in the scene
Why do we collect evidence?
allows investigators to rebuild events, determine course of events, discover key participants
Different forms of evidence
DNA evidence
physical evidence
impression evidence
trace evidence
biological evidence
What are the expected actions, limitations, responsibilities, and objectives of a first responding officer?
- bring the site under control
- coordinate the employment of available resources
- document info provided
- ensure officer safety
- provide emergency care
- secure and control scene and all those in it
- release scene to appropriate authority
- define initial perimeter
- primary focal points
- exit points
- secondary scenes
- entry log
What is the purpose of creating a scene perimeter and how is it done?
the purpose is to make sure nobody is contaminating the scene
it is done by finding primary focal points, natural entry and exit points, secondary scenes
Why is it important to follow a sequence of crime scene processing?
It is important to follow a sequence of crime scene processing because it is important to make sure you don’t leave anything out, a sequence is the best way to ensure all evidence is collected
What are the actions/differences behind the 6 crime scene activities?
assessing
- scope and complexity of the scene
- scene integrity and contamination control
- term approach and composition
- search methods to be used
- personal protective measures
observing
- requires walk though, but without altering anything, since sketching and mapping have not been completed
- use an 8-step descriptive set: quantity, item, color, type of construction, approximate size, identifying features, condition and location
documenting
- walking through, creating written notes of basic observations
- photographing the scene, without altering or changing it
- videotaping the scene
- sketching and measuring the scene
- close-up photography of specific details and artifacts that may require manipulation
searching
- move through the scene, items have to be moved, and all surfaces examined
- because of this searches are accomplished in stages
- the initial observation is a form of visual search
- true initial searches are done with limited alteration of the scene to prevent disturbing any unobserved evidence
- later searches are extremely intrusive, often requiring dismantling and movement of objects in the scene
collecting
- intrusive action
- disturbing context of the item and scene forever
- no undoing this action
collecting occurs only after all evidence has been documented
analyzing
- intrusive behaviors
- large scale latent print processing of walls and furniture
- chemical enhancement of latent prints of bloodstains on floors, wall or obejcts
- forensic analysis of specific objects of evidence at the crime lab
What are the different search patterns and why would you choose one over the other?
Line search
grid search
zone search
circle search
point to point search
