CSI FINAL Flashcards
Lividity
pooling of blood in lowest parts of the body due to gravity after death
Rigor Mortis
stiffening of muscles after death
Algor Mortis
cooling of body post-mortem
Livor Mortis
discoloration caused by blood settling in body
purpose of fire investigation
determine origin and cause of fire
Problems with fire investigations
potential contamination, destruction of evidence, and hazards like structural instability
What to identify at fire scene
- V patterns from smoke, soot, flames
- burn intensity and directionality
- presence of accelerants
What to include in a diagram
- measurements and scale
- evidence locations and landmarks
- north direction indicator
- labels and legend
when to create sketches
- after initial observation
- when documenting evidence placement
benefits of crime scene photography
- creates permanent record
- provides details for reconstruction
problems with crime scene photography
- lighting issues
- camera malfunctions
- misorientation or confusion in photos
forms of documentation
notes, photos, sketches, reports
when establishing perimeter at scene
- locate furthest evidence
- identify primary and secondary scenes
- block suspect’s access points
- preserve perpetrator’s movement trail
what are ballistics
- casings, GSR, rifling marks
- used to analyze bullet markings, ejector and firing pin impressions
issues with crime scene integrity
- contamination of evidence
- poor documentation or chain of custody breaches
Scientific Method
apply a systematic approach:
- observe, hypothesize, test, analyze, and conclude
Crime Scene Processing Methodology
- assessing scene
- observing
- documenting
- searching
- collecting evidence
- analyzing
duties of first responding officer
- secure scene
- provide medical assistance if necessary
- preserve evidence
- establish perimeter
bloodstain patterns
directionality (tail of bloodstain), spatter, castoff
How to measure bloodstain
angle of impact: inverse sin (width divided by length)
fingerprinting considerations
surface type: smooth, porous, nonporous
techniques: dusting, chemical treatments (ninhydrin, superglue fuming)
photographing body
position, injuries, surroundings, move after thorough documentation
Dealing with buried remains
- establish perimeter
- document scene before digging
- carefully remove dirt in layers
- screen all soil for evidence
types of bloodstains
- passive (drops, pools)
- transfer (smears, swipes)
- spatter (impact, castoff)
crime scene reconstruction involves
- linking evidence to actions
- determining sequence of events
personal protective equipment
goggles, gloves, hazmat suit
crime scene search patterns
circle, grid, line, zone
impression evidence
shoeprints, tire tracks
types of DNA
mitochondrial (maternal lineage), Y-STR (paternal lineage), Nuclear DNA (unique profile)
Locard’s Principle
- every contact leaves a trace
- prevent contamination during evidence collection
when approaching a scene
- secure area
- observe and document initial conditions
- protect evidence from contamination
- begin systematic processing
