l3 CSI Flashcards
define crime scene
any place where a crime has been committed
what is the primary scene? secondary scene?
primary is the site of the original criminal activity, secondary is any subsequent location
what is ‘macroscopic’ when referring to a scene
refers to overall crime scene
what is ‘microscopic’ when referring to a scene
trace evidence or ‘smaller scenes’
what are the three major avenues available to investigators when solving crimes?
confessions, eyewitness accounts, physical evidence
why is physical evidence so important?
only thing free of error or bias
the likelihood that a suspect and victim are connected depends on..?
number of pieces of evidence linking them AND uniqueness of evidence
probability of two individual events occuring together can be calculated by multiplying the individual probability of each event occurring alone
the product rule
most experienced individual responsible for managing the crime scene
lead investigator
the first person at the scene of a crime
first responder
what is important to ensure when first responders detain witnesses? why?
keep witnesses seperate, do not let them revisit scene, keeps them objective
5 duties of a first responder
- assist victim, prevent any changes to victim
- search for and arrest suspects
- detain witnesses
- secure scene
- document all movement/changes to scene
first examination/ orientation of scene by investigator
preliminary scene survey
what is transient evidence?
physical evidence that can be easily lost or altered if not preserved properly
what is conditional evidence?
evidence produced by specific event or action
single most important task of a crime scene investigator
generate permanent record of scene and it’s physical evidence (documentation)
what are the 4 major documentation tasks?
- note taking
- videography
- photography
- sketching
after assisting victims and arresting suspects, the first officer arriving at the scene should..?
secure the scene
police barricades and guards prohibit access to a crime scene for..?
all unauthorized personnel
sucess in regoctinion and collection of evidence is primarily determined by..?
skill of personnel processing the scene
evidence collector must ensure there is no potential contamination from transferring their DNA onto evidence by..?
wearing a face mask
t/f main objective of packing and collecting physical evidence is to prevent any change in evidence from time it’s removed from scene and time it’s received by a lab
true
t/f a rough sketch of a scene does not need to accurately depict dimensions of the scene
false
search method that has two people performing line searches that originate at adjacent corners and form perpendicular lines
grid search
search method that has one or two people walking in straight lines across the scene
line/strip search
search method where scene is divided into smaller sections with a person assigned to each sections, sections may be further divided
quadrant/zone search
search method; move in inward spiral from boundaries to center, or outward from center to barriers
spiral search
draft representation of all essential info and measurements at a scene
rough sketch
precise rendering of a scene, usually drawn to scale
finished sketch
initial survey of the scene carried out by lead investigator where they gain an overview of the scene in order to create a plan for processing
walk-through
chain of custody
list of all people who came into possession of an item of evidence
search method, where several people move from the boundary toward center (inward) or from center to boundary (outward)
wheel/ray search
standard/reference sample
physical evidence whos orgin is known, that can be compared to crime scene evidence
examples of a standard sample
blood or hair from a suspect
buccal swab
swab of inner potion of the cheek
uncontaminated surface material close to an area where physical evidence is deposited
substrate control
example of substrate control
unstained portion of a bloody t-shirt
when should videography be performed? what should it not include?
after first walkthrough, should not include people, equipment or audio
photo log
record of all crime scene photographs ith details
t/f it is okay to delete or not log accidental photos
false
what is the importance of sketching, what can it provide that other documentation cannot?
proper perspective and perspective of evidence in the scene
how is a chain of custody ensured?
evidence sealed and initialed by collector, date, location and time collected are included
