1
Q
What is the end goal of crime scene processing?
A
The collection of the evidence and scene context in as pristine a condition as possible.
2
Q
Six basic steps of crime scene processing
A
Assessing
Observing
Documenting
Searching
Collecting
Analyzing
3
Q
In a free society, the police have two basic goals. What are they?
A
- The prevention of crime and disorder, and the preservation of peace
- The protection of life, property, and personal liberty
4
Q
To achieve their basic goals, the police apply 5 basic objectives. What are they?
A
- Crime Prevention
- Crime Repression
- Regulating Noncriminal Conduct
- Provision of Services
- Protection of Personal Liberty
5
Q
Evidence can be defined as ________________.
A
Anything that tends to prove or disprove a fact in contention
6
Q
Evidence presents itself as _____________________ and ______________________
A
Physical Evidence
Testimonial Evidence
7
Q
According to Rynearson and Chisum, context can manifest itself in a number of ways. These manifestations are classified as:
A
Predictable effects
Unpredictable effects
Transitory effects
Relational detail
Functional detail
8
Q
CSIs should ask these 4 questions about any piece of evidence
A
What is it?
What function did it serve?
What relationship does it have to any other items of evidence or to the scene itself?
What does it tell us about timing and sequencing aspects?
9
Q
____________ aspects allow us to place the time of the crime in some form or fashion
___________ aspects help the CSI decide in what order the crime occurred
A
Timing
Sequencing
10
Q
The 5 basic ingredients to a good processing methodology
A
Knowledge
Skills and tools
A methodical approach
Flexibility
A coordinated effort
11
Q
3 specific scene-integrity issues
A
The addition of material to the scene
The destruction of material in the scene
The movement of material in the scene
12
Q
What is the investigative standard?
A
Beyond reasonable doubt
Police can arrest based on probable cause though
13
Q
The characteristics present by all physical evidence can be classified in 2 categories. What are they?
A
Class characteristics
Individual characteristics
14
Q
Locard’s Exchange Principle is stated:
A
“Every contact leaves a trace”
15
Q
Cross Contamination is caused by what?
A
Inappropriate handling of evidence
16
Q
What is mechanical fit?
A
Where an item is damaged and the pieces are deposited in the scene. Pieces can then be fit together.
17
Q
Fingerprint evidence provides (class/individual) characteristics
A
Individual
18
Q
When do people develop their fingerprints?
A
In the human fetus at about 12 weeks
19
Q
Three basic ridge patterns and the percentage they make up
A
Loops - 65%
Arches - 5%
Whorls - 30%
20
Q
Ridge Identification Characteristics - Modern 3
A
Dot
Bifurcation
Ending Ridge
21
Q
ACE-V Methodology
A
Analyze
Compare
Evaluate
Verify
22
Q
Fingerprints consist of approximately ____ water
A
98%
23
Q
Fingerprints consist of approximately ____ of grease, oils, salts, and amino acids
A
2%
24
Q
Latent vs Patent vs Plastic
A
Latent = invisible
Patent = visible
Plastic = 3D impression in soft surface
25
Several factors increase or decrease the probability that identifiable prints will be found on a surface, including, but not limited to:
The amount of pressure between the friction ridge surface and the substrate
The duration of contact and the nature of contact
Substrate characteristics
Depositor characteristics
26
Biological evidence exists in the form of what?
Blood
Saliva
Semen
Vaginal Fluid
Any other form of DNA source like bones or tissue
27
Class characteristics in blood
Blood Type (A, B, AB, O)
Blood Antigens
28
Which has a nucleus?
a. White Blood cells
b. Red Blood Cells
c. Both
d. Neither
a. White Blood Cells
29
Basic subunits of of genes and their pairings?
Guanine (G)
Cytosine (C)
Adenine (A)
Thymine (T)
G-C
A-T
30
Who is mDNA inherited from?
Mother
31
Hair analysis commonly uses what?
mDNA
32
Trace evidence includes what?
Hair
Fibers
Glass
Paints
Soil
33
___% of any transferred hair or fibers are lost in the first ___ hours following contact
90
8
34
3 basic determinations from glass examination
Glass type
Direction of force
Sequence of force
35
4R Rule
Ridge lines on Radial fractures form Right angles to the Rear
36
What type of scene accounts for a significant number of paint analysis requests?
Hit and run accident scenes
37
Soil samples should be packaged in what?
small, clean, pint-sized paint cans
38
How much soil should be collected?
1/2 cup to 1 cup of material
39
Gunshot residue (GSR) contains what 3 elements?
Antimony
Barium
Lead
40
Parts of a Cartridge
Projectile
Cartridge Case
Propellant
Primer
41
What is rifling?
A series of grooves manufactured into the barrel of the weapon that gives the projectile spin. Rifling puts lands and grooves on on projectiles
42
Categories of tool mark impressions
Striations
Compression
Drill
43
Striations are caused by what?
Cutting edge of a tool is slid against target
44
Compressions are caused by what?
A tool is forced into a softer material
45
Impression evidence includes what?
Shoe marks
Tire marks
Bite marks
Tool marks
Plastic fingerprints
46
Class characteristics of tire marks
Tread design
Noise treatment
Treadwear bars
47
How to measure track width?
Measure the width across the front or rear axle
Measure from outside tread to opposite outside tread or inside tread to opposite inside tread
48
Class characteristics of shoe marks
Sole shape
Size
Tread pattern
49
What is the type of lighting used for documenting shoe or tire marks?
Oblique lighting
50
Where do bite marks occur?
Human skin
Uneaten food with a bite in it
Clenching something in teeth, then leaving it behind
51
Chemical analysis instrumentation
Gas chromatography - Mass spectroscopy (GC-MS)
UV and IR spectrometry
Etc
52
Sample size of liquids required for analysis?
10cc
53
Tracing is what?
A conscious effort to copy a known writing
54
Why can ALS detect alteration of writings
Inks fluoresce at different wavelengths
55
How are indented writings recovered
Electrostatic detection apparatus (ESDA)
56
Computer analysis includes?
determining content of drives and media
comparing data files
establishing when a file or action was created or conducted
recovering deleted information and files
decrypting password-protected systems, files, or media
57
Standard approach for cell phone collection
Collect and isolate
58
3 ways to isolate a cell phone
Place device in airplane mode
Turn device off
Place device in Faraday device
59
A __________ pathologist works in a hospital and is concerned with cause of death
A _________ pathologist is concerns with manner of death, cause of death, and interval of death
Clinical
Forensic
60
Manners of Death
Homicide
Suicide
Accident
Natural
Undetermined
61
What defines specific responsibilities within the organization?
Standard Operating Procedures (SOPs)
62
Goals of the first responding officer
Bring site under control
Coordinate resources
63
5 objectives of the first responding officer
Document provided information
Not become a casualty
Provide for emergency care
Secure and control the scene and all those within
Release the scene to the appropriate authorities
64
Inviolable Rule regarding emergency care
Lifesaving always takes priority over evidence preservation
65
What is the EMS bomb?
Disturbance/destruction of the crime scene due to EMS actions
66
When deciding to establish an initial perimeter, the officer should consider these 3 things
Primary focal points
Natural entry/exit points
Secondary scenes
67
Documentation includes what?
Notes
Photographs/Videotapes
Sketches
Reports
68
The purpose of assessment by the CSI team is to consider the following (5):
Scope of the scene
Scene integrity and contamination control
Team approach and composition
Search methods to be used
Personal protective measures
69
4 techniques to handle supervisors or politicians
Enforce the use of PPE
Enforce the use of scene entry logs
Consider creating walking routes or observation points for authorized visitors
The use of 3D scanning systems to create virtual scene visits for supervisory personnel
70
Primary considerations for entry/exit points
What avenue of approach or departure did suspect utilize
Will the access point expose operations to unnecessary media scrutiny
What access points are available
71
In the _________ approach, the team leader designates different teams to do different activities
In the __________ approach, a single group of investigators is responsible from all processing for a given area in the scene
Functional
Area
72
How many members does the photography team require?
at least 2 people
73
How many members does the sketch and measurement team require?
generally 3 people
74
How many members does the evidence collection team require?
at least 2 people
75
"_____________" is defined as "marked by ordered and systematic habits or behaviors"
"_____________" is defined as "purposefully regular"
Methodical
Systematic
76
Factors to consider regarding the area or search swath a single searcher is responsible for
Nature of ground being searched
Lighting conditions
On-scene environmental conditions
Size of item being searched for
77
What is the most important tool of the crime scene searcher?
Clean white light
78
5 basic search patterns
Spiral
Strip and Line
Grid
Zone
Point to point
79
Full scope of hazards on a scene include:
Biohazards from blood and other body fluids
Structural hazards found in fire and explosion scenes
Chemical and inhalation hazards found in fire scenes
Inhalation, chemical, and fire hazards from on-scene processing methods
Inhalation, chemical, and explosion hazards from drug labs
Biochemical hazards associated with terrorism
80
Primary biohazards associated with body fluids are?
HIV
Hepatitis (HAV, HBV, HCV)
81
How is HIV transmitted
contact with blood, semen, and vaginal secretions
82
The HIV virus can remain active for up to ___________ in a dried form, and when wet, for even longer
3 to 5 days
83
HAV or HBV
____ is primarily transmitted through oral or fecal routes
____ is primarily transmitted through direct and indirect contact with blood or body fluids
HAV
HBV
84
What does HCV attack?
Liver
85
Durable equipment should be washed with a _____ dilution of bleach to water
1:10
86
Good photographs require?
Physical control of the camera
Proper use of camera controls
Proper composition
87
What is the purpose of a crime scene photograph?
to accurately depict the scene without introducing distortion or visual bias
88
Significant comprehension problems for viewer of the photographs the photographer takes includes:
Identification problems
Orientation problems
Incomplete documentation
89
Types of Crime Scene Photographs
Overalls
Midrange/Evidence-Establishing
Close-Ups/Forensic Quality
90
Roadmapping Steps
Recognition of discrete patterns or defects
Placement of appropriate labels and scales
Creation of overall photographs of an area with labels in place
Creation of overall photographs of a pattern with labels in place
Creation of additional midrange photographs of individual stains or details when needed
Creation of close-up photographs of individual stains, defects, or details with labels in place
91
In roadmapping, the rule is that no photograph is ever taken without ________________________________
at least one label framed in the photograph
92
______________________ effectively defines the the blood source was in a 3D space when it received the force to create the impact pattern
Area of Origin
93
How many stains should be chosen for an area of origin analysis
10 - 15 stains
94
Court questions to challenge a crime scene photograph
Does the photograph accurately depict the scene?
Is the photograph generally free of distortion?
95
Most crime scene photography is accomplished with these lenses:
28mm (overalls)
50mm
50mm macro lens
96
3 basic aspects of the camera the photographer must control
Physical control
Light
Focus and Depth of Field
97
In offset flash, the flash is held at a _____ degree angle and an ________ length away
45
arm's
98
Depth of field relates to:
the focus of objects in front of and beyond the subject
99
the higher the f/stop, the ___________ the aperture
the lower the f/stop, the ___________ the aperture
smaller
larger
100
Can video footage replace photography
No
101
5 basic elements of a sketch
Heading
Diagram area
Legend
Title block
Scale and direction notations
102
Points of view in a crime scene sketch and what do they depict
Bird's-eye view - horizontal
Cross-projection or exploded - vertical and horizontal
Elevation - vertical
3D - realistic perspective
103
Mapping Methods (6)
Rectangular coordinates
Triangulation
Baseline coordinates
Polar coordinates
Triangulation or Rectangular coordinates on a grid
Triangulation on a baseline
104
Regular objects get ____ measurements
Irregular objects get ____ measurements
4
2
105
Digital scene mapping methods
Total station systems
3D laser scanning methods
106
3D laser scan system is designed to automatically scan and record millions of points in an arc of ____ degrees and ____ degrees around the machine
360
270
107
It is imperative scene note descriptions be
Detailed
Accurate
Understandable
108
The CSI's notes should start with notification of the crime, specific actions upon arrival and what?
a clear record of all observations and action taken in the scene
109
When an area has no relevance to the crime, the CSI should note that that area is _______________
unremarkable
110
A report should NOT be
A cursory discussion on central items and nothing more
A rambling discourse on way the suspect had to have committed the crime
A description of only the evidence that fits a particular hypothesis
111
Suggested format for reports
Introduction
Characteristics of the scene
Conditions of the scene
Environmental conditions
Factors pertinent to entry and exit
Scene documentation
Collection of physical evidence
Search of latent prints
Additional examination
112
______________ is the critical component of any final crime scene report
Objectivity
113
Radiant energy is measured by the length of its wave from _________________
Peak to peak
114
A nanometer (nm) is _________________ of a meter
one-billionth
1,000,000,000
115
Radiant spectrum starts with ___________________ (1-200nm) an includes ___________ (12,000nm)
Gamma and X-rays
Heat
116
The _________ the wavelength, the greater the energy, the __________ the penetration the wave has on an object
Lower
Greater
117
How can light act on an object?
Absorbed
Transmitted
Reflected
Converted
118
What defines the color of any object?
Reflection of light
119
_______ represents a reflection of all wavelengths
_______ represents an absorption of all wavelengths
White
Black
120
_____________ is where the light passes through an object
Transmission
121
Conversion is where light is converted from one wavelength to another. This is also called what?
Luminescence
122
___________ occurs when an object is exposed to an active energy source
____________ occurs when an object continues to give off light even after removal of the energy source
Fluorescence
Phosphorescence
123
Barrier filters _________ the original wavelength, allowing the converted wavelength to be __________
eliminate
observed
124
UV (________nm) is broken into 3 categories:
UVA (________nm)
UVB (________nm)
UVC (________nm)
200-400nm
320-400nm
280-320nm
100-280nm
125
RUVIS stands for what and uses what type of UV?
Reflected UV Imaging System
UVC
126
All RUVIS uses shortwave UV in this wavelength?
250nm
127
What is RUVIS used for?
Enhancing cyanoacrylate latent prints
128
Longwave UV (UVA) can be used for what?
locating bloodstains which absorb UVA
locating semen, spittle, salvia which all fluoresce
129
Near-UV and violet light at 450nm can visualize what with a yellow barrier filter?
Bite marks and bruises on human skin
130
At 455nm, what can be observed with an orange filter?
biological fluids
131
At 485nm, what can be observed with a yellow filter?
latent prints developed with ninhydrin
132
The orange and red wavelengths are effective for viewing what?
Inks and subcutaneous bruising
133
_________________ hairs will fluoresce. ________________ will not fluoresce.
Some red or blonde
Dark hairs
134
___________________ is the best resource when seeking any hairs
Oblique lighting
135
IR light (700-2000nm) is most often used with what?
Ink differentiation
Bloodstain and GSR location (absorb IR)
Bruising (absorb IR)
136
Thermal Imaging (12,000nm) are often used with police air operations, but have also been used to locate what?
decomposing bodies
hot spots in fire scenes
137
Fingerprint friction ridges are found where?
Palmar side of hands
Plantar side of feet
138
2 principles of friction ridge skin
Individuality
Permanence
139
___________ is the application applied to fingerprint pattern interpretation, ridge counting, and ridge tracing
Classification
140
Before AFIS, what was the primary classification system?
the Henry Classification System
141
Instead of patterns, what does AFIS use?
an algorithm based on spatial orientations of ridges
142
Basic types of surfaces encountered by fingerprints
Porous
Nonporous Smooth
Nonporous Rough
Special Conditions (human skin, adhesive tapes, blood prints)
143
____________________________ define the fingerprinting method used, following by if the surface is _____ or ____
Surface characteristics
Wet
Dry
144
Chemicals for porous surfaces include
Iodine
Ninhydrin
DFO (1,8 diazfluoren)
Physical developer
145
Iodine produces what color prints?
dark brownish
146
Ninhydrin (2,2-dihydroxyindane-1,3-dione) reacts with what in the print and produces what color?
Alpha-amino acids
Ruhemann's purple
147
DFO produces what color and is visualized how?
Fluorescent orange
Cyan light with orange barrier filter
148
Why is physical developer always last?
It will wash away all constitutes of fingerprint residue
149
What does physical developer react with?
salts, fats, and waxes in the print
150
Physical developer requires the mixing of what?
several solutions
Silver Nitrate
Prewashes
Rinses
151
How are prints on nonporous smooth surfaces stabilized?
Cyanoacrylate fuming
152
Methods for nonporous smooth surfaces
Brush and powder
Dye stains like Rhodamine 6G, Ardox, and RAM
Fluorescent powders
Small particle reagent (SPR)
153
Methods for nonporous rough
Cyanoacrylate fuming and dye stains or powder and brush
154
How to lift print from nonporous rough
Rough-surface lifting tape
Silicon lifting material
Gel lifters
Mikrosil or Accutrans
50/50 water and glue
155
Why can't normal lift tape be used with nonporous rough?
Lift will result in fragmented condition or background pattern will lift and block detail form latent
156
How to process human skin
Magnetic powder and brush
Iodine fuming
Adding-Machine-Paper Process
Cyanoacrylate fuming
157
How to process adhesive tape
Crystal Violet
Wet powder (WetWop)
158
What do you do if adhesive tape is balled up and can't be processed?
Freeze it or use a solvent solution
159
How to process bloody prints
Amido-black
Leuco-crystal violet
Fluorescein (alcohol-based)
160
How to process polystyrene materials
Magnetic powder
Cyanoacrylate fuming
SPR
161
Cyanoacrylate fuming was developed in the _____ by the _____________
Late 1970s
Japanese
162
How does cyanoacrylate fuming work?
Superglue reacts with the print and polymerization occurs to stabilize the print
163
By the _______, cyanoacrylate fuming was a standard on-scene process
Early 1980s
164
The continued spread of training and understanding of cyanoacrylate fuming at the scene has led to a _______ greater potential for identifying a suspect
400%
165
Cyanoacrylate fuming does not hinder other processes such as DNA, drug identification, and firearm examination. What evidence is affected by cyanoacrylate fuming?
Trace evidence
166
The most common dye stains today are?
Basic Yellow
RAM (Rhodamine 6G, Ardox, P-Methoxybenzlamino-4Notrobenz-2-O-XA-1,3-Diazile)
167
2 issues regarding brush and powder
Overpowdering a print
Applying too much pressure when dusting
168
This type of brush is the typical brush used for dusting a surface.
Fiberglass brush
169
Latent print brushes include
Fiberglass brush
Camel/goat-hair brush
Feather/maribou brush
Etc
170
Fluorescent powders are particularly useful on these types of surfaces.
Multicolor surfaces , where consistent contrast under normal lighting is impossible
171
______ lifters are designed primarily for use in situations where the surface involved is irregular or curved.
Rubber
172
SPR was developed as a method to recover latent prints from what surfaces?
Wet surfaces
173
SPR consists of what?
Molybdenum disulfide suspended in a water solution
174
What does SPR react with?
Fats
175
Components for Adding machine paper Process
Adding Machine Paper
Magnetic brush with a fine powder
Pencil or pen
176
Two proven powders best for adding machine paper process
Moonglo
Midnight Blu
177
Is the type of adding machine paper a factor in if the adding machine paper technique is effective?
No
178
When doing the adding machine paper technique with a manual strangulation, is it wiser to apply the paper vertically or horizontally to the length of the body?
Vertically (across the neck)
179
How to recover latent prints from a fire scene
Camphor technique - Expose surface to a gentle flame by burning camphor, then dust soot off which exposes the print
180
Camphor is particularly useful for what surface?
Metal
181
How is known tenprint information captured today?
Livescan
182
With impression evidence, what angle should your flash/light be held at?
45 degrees
183
How far should the flash/light be held from the impression?
2ft to 3ft
184
What are rubber casting compounds used for?
Tool marks
Plastic prints
Latent prints from rough surfaces (or curved surfaces)
185
What surfaces are rubber casting compounds most effective for?
Hard substrates
186
What is a rubber casting compound made of?
Base material
Curing compound
187
Electrostatic Dust Lifters (ESDL) work on what concept?
Opposites attract
188
Electrostatic Dust Lifters (ESDL) were developed in _______ in the ________
Japan
1970s
189
What surfaces can Electrostatic Dust Lifters (ESDL) be used on?
Almost any including floors, walls, doors, other hard surfaces, clothing, carpets, paper
190
Is the Electrostatic Dust Lifter (ESDL) effective on wet surfaces?
NO!
191
What charge does the Electrostatic Dust Lifter (ESDL) create?
15,000 volts
192
How to locate dust impressions
Oblique lighting
193
Why is dental stone an effective cast for footwear and tire impressions?
It sets harder
Is more forgiving of error during mixing
Tends to recover more detail than standard plaster
May not require a form mold
194
Impressions made in loose soil, powders, or sand may benefit from what?
Treatment by a fixative
195
What consistency should properly mixed dental stone be of?
Pancake batter
196
How long should you let dental stone dry for?
At minimum, 20-30 minutes
197
Can dental stone be used on 2D impressions?
Yes
Particularly wet prints on concrete
198
What is a primarily method for casting prints in snow?
What is another method?
Dental stone (allow dental stone to cool before pouring)
Dry casting
199
What is highlighting in terms of snow impressions?
Spraying a dark-colored spray-paint from the height of at least 8 inches
200
____________ is a measurement of the distance between opposite side wheels. This is measured from the inside of one impression to the outside of the other impression.
Tire Track Stance
201
___________ is a measurement from the center of a front wheel to the center of the same side rear wheel. This measurement is only possible when deep, static impressions are left after a vehicle has stopped.
Wheelbase
202
__________________ is the smallest radius that a particular vehicle can turn in a circle. This is a class characteristic.
Turning radius
203
____________________ are the most effective tools for collecting 2D impressions
Gelatin and adhesive lifters
204
Gelatin lifters can be used on what surfaces?
Almost any including textured and porous surfaces
205
Tire Data that should be documented includes (7)
Manufacturer
Brand
Type/Model Number
Size
Serial Number
Tread Depth
Significant Wear
206
_____________ is a complete unit of unfired ammunition. Typically this is made up of a bullet and casing, with primers and propellant contained within
Cartridge
207
_______________ is the sub-unit of the cartridge that holds the primer and propellant. This is typically made of metal and will either be expelled from automatic and semi-automatic weapons or retained in single sot or revolver type weapons
Cartridge Case
208
______________ is the sub-unit of a cartridge that is expelled from the firearm under the pressure created by the burning propellant. These are typically a single mass of metal with varying constructions (eg solid lead, semi-jacketed lead core, fully jacketed lead core). This can be in some instances "shot" consisting of various sized small lead or steel balls, expelled in mass from a long bore weapon (eg shotgun) or in some instances from handguns and other weapons (eg snake-shot cartridges)
Projectile/Bullet
209
____________ is the location of the firearm that holds the cartridge when it is fired
Chamber
210
____________ is the tubular aspect of the firearm that directs the path of the projectile when fired from the ammunition
Barrel
211
_______________ is associated with semi-automatic and automatic weapons. This is where the expended casing is ejected from the chamber
Ejection Port
212
Ballistics is broken down into 3 areas of study:
Internal or interior ballistics
Terminal ballistics
External or exterior ballistics
213
Name the people involved.
_________ deal with internal ballistics
_________ deal with terminal ballistics
_________ deal with external ballistics
Forensic Firearms Examiners
Forensic Pathologists
CSIs
214
Questions the firearms examiner attempts to resolve:
Does the weapon operate as intended?
Can it operate at all?
Are there any aspects of the weapon capable of creating some form of accidental discharge?
215
Areas of study by the firearms examiner
Evaluation of ejection patterns
Evaluation of gunshot residue patterns and shotgun shot patterns
Examination of bullets and bullet fragments for trace evidence and damage
216
Characteristics on a bullet or bullet fragment
Layering of trace evidence, indicative in sequence of targets struck
Damage to the projectile, indicative of type of target the bullet struck
Deformation of the projectile, indicative of a deflection along its flight path and angle of deflection
217
___________________: The muzzle is in direct contact with the skin or pressed into the skin
Close contact or hard contact
218
___________________: The muzzle is in extremely close proximity to the skin, but at the moment of firing, a small gap is created between the two
Loose contact
219
___________________: The muzzle is generally said to be not more that 5in from the skin
Near contact
220
___________________: The muzzle is typically between 5in and 40in (max distance may be altered). This distance is deduced from the presence of stippling around the wound
Intermediate range
221
___________________: No conclusion can be drawn on muzzle distance. There is no resulting effects (soot, searing, stippling) except for the bullet defect.
Indeterminate range
222
Bullet injuries:
______________: where the bullet enters but does not exit
______________: where the bullet enters and exits
______________: where the bullet skims the surface, producing several shallow wounds
______________: where the bullet leaves only a minor abrasion as it passes adjacent to the body
Penetrating
Perforating
Tangential
Grazing
223
_________________ considers the trajectory of the bullet after leaving the barrel. The information derived is dependent upon what?
External ballistics
The scene and the targets involved
224
Bullet defects:
______________: where the bullet enters but does not exit a surface
______________: where the bullet enters and exits a surface
______________: where the bullet strikes a surface and deflects off it at some angle without penetrating the surface completely
______________: where the bullet skims a surface, creating a series of defects
Penetrating
Perforating
Ricochet or Deflection
Tangential
225
When dealing with defects associated with __________________, visible fragments may not be present to aid in this verification. Chemical tests can aid in verifying a defect as a bullet defect
Ricochets or tangential impacts
226
__________________ consist of fused particles of barium, antimony, and lead and can be examined using a scanning electron microscope (SEM)
Primer residues
227
Sodium rhodizonate is used to test for what?
Presence of lead
228
What color is a positive sodium rhodizonate test
Scarlet
Blue-Violet once HCl is added
229
Dithio oximide (DTO) tests for what?
Copper
230
What color is a positive Dithio oximide (DTO) test?
Green
231
The Modified Griess test tests for what?
Nitrite compounds
232
What color is a positive Modified Griess test?
Orange
233
Impact angles for bullet defects can be determined by this equation:
SIN^-1(width/length)
234
In a bullet defect, the ______________ will often present a clean margin while the far edge produces a rough appearance.
leading edge
235
_________________: This is the angle of the muzzle in relation to the target using a horizontal reference line. It shows movement right or left and is measured using a protractor aligned with a horizontal plane.
Horizontal angle or angle of departure
236
_________________: This is the angle of the muzzle in relation to the target using a vertical reference line. It shows movement up and down and is measured using a protractor aligned with a vertical plane or the standard angle finder.
Vertical angle or angle of elevation
237
_____________ involves small fracture lines on the paint arcing out and away from the defect. Line extend opposite the direction of travel
Wake effect
238
The ______ laser is preferred over the _____ laser because the _______ laser is easier to visualize than the ______ laser
Green
Red
Green
Red
239
If evaluating a bullet path less than _____, the bullet is assumed to have been traveling in a straight line rather than a parabolic arc
30m
240
Zones of Possibilities
Zone 1: An area considered ...
Zone 2: An area considered ...
Zone 3: An area considered ...
Most probable. Shoulder height or lower
Possible but awkward. Higher than the shoulder
Impossible given the data
241
BPA considers what aspects of the blood stains?
Location
Size
Distribution
Other physical characteristics
242
Blood is a __________ fluid
non-Newtonian
243
The variations in combinations of blood volumes and forces acting on those volumes lead to recognizable classes of patterns
The Pattern Diversity Principle
244
6 mechanisms of bloodstains
Static blood dispersed from a point source
Blood dispersed in a jet (streaming ejection)
Blood dispersed as a function of accelerated motion
Blood that accumulates or flows on a surface
Blood dispersed as a function of gravity
245
The shape of certain bloodstains provides indicators as to the direction of deposition as well as to the spatial origin of the blood
The Principle of Stain Shape and Vector Correlation
246
The collapse of a free flight droplet on a surface produces a stain with a circular or elliptical shape. These stains may have spines, scallops, or satellite stains. These characteristics, if present, may define direction of travel for the droplet at the moment of impact
The Principle of Stain Shape and Vector Correlation: Directional Angle
247
The collapse of a free flight droplet on a surface produces a stain with a circular or elliptical shape. The ratio between the length of the long and short axes of the resulting stain has an empirical relationship to the angle at which the droplet struck the target
The Principle of Stain Shape and Vector Correlation: Impact Angle
248
A droplet of liquid in flight is what shape?
Sphere
249
Considered together, the impact and directional angles for a number of stains associated with an impact event may define the origin of the stains in three dimensions
Area of Origin corollary
250
Once exposed, blood will react to environmental conditions (air flow, temperature, humidity, variation of surface) in a predictable manner
The Physically Altered Bloodstain Principle
251
BPA Methodology
Becomes familiar with entire scene
Identifies discrete patterns among various bloodstained surfaces
Classifies these patterns based on physical characteristics using some form of established taxonomy
Evaluates aspects of directionality and motion in the stain or pattern
Evaluates angles of impact, points of convergence, and areas of origin (if necessary)
Evaluates interrelationships among stains, patterns, and other evidence
Evaluates viable source events to explain the pattern (based on all of the above)
Validates the analysis through some form of peer review
252
A primary aspect of BPA is to ...
recognize and classify the various bloodstain patterns
253
Classification is problematic because why?
There are numerous classification systems currently being utilized
254
Bloodstain pattern evidence is (class/individual) characteristic evidence
Class
255
Stains created when blood is ejected in a stream under pressure or with velocity, most often encountered when an artery or heart is breached
Spurt
256
Stains created when blood is flung from an object that is either in motion or which suddenly stops some motion
Cast-Off
257
A pattern of individual spatter deposited on a surface, demonstrating movement of the dripping item from one point to another
Drip Trail
258
A radiating pattern of circular or elliptical shaped stains created when blood is broken up at a source by some force
Impact Pattern
259
Spatter resulting from blood dripping from an individual or otherwise bloodied object
Drip(s)
260
An irregular pattern created when blood is ejected in volume
Gush/Splash
261
A pattern of spatter deposited into one another or into another liquid, resulting in an accumulation and secondary spatter randomly oriented around the stain
Blood into Blood
262
Any stain or pattern created by the transfer of blood from one object onto another, through some form of contact
Smear
263
Any stain or pattern created by the transfer of blood from one object onto another in which a recognizable characteristic or image is present in the pattern
Pattern Transfer
264
Blood flows always obey what?
Gravity
265
This nonofficial pattern can mimic to some degree impact spatter, appearing as a number of small circular stains. In some instances, they may also mimic directional spatter
Fly Spot
266
Two primary presumptive blood test
Phenolphthalein
Leucomalachite Green
267
Presumptive blood tests are based on what type of reaction and in the presence of what?
Oxidation--Reduction
Heme
268
Luminol consists of what?
Distilled water (100mL)
Luminol (3-aminophthalhydrazide) (0.1g)
Sodium perborate (0.7g)
Sodium carbonate (0.5g)
269
Fluorescein reacts with what?
Heme under an ALS (455nm - 485nm)
270
What color barrier filter works with fluorescein
Yellow
Orange
271
Water-based amido black should only be used on what surface?
Static surfaces
272
What is the process where firefighters search for hot spots that might flare up and are eliminated if found?
Overhaul
273
Fire is a (endothermic/exothermic) reaction
Exothermic
274
Fire Tetraheadron
Fuel
Heat
Oxygen
Chemical Chain Reaction
275
Fire flows in what direction?
Up and outward
276
What demonstrates how far the hot gas layer extended down?
Line charring
277
What do fire patterns do?
Show progress of the fire
Demonstrate the nature of the fuels involved
Help to locate and isolate the origin of the fire
278
What is the primary problem associated with searching for fire damage?
The level of damage present in the scene
279
Where are points of origins often found in fire scenes?
In proximity to low burn patterns
280
Rules of Thumb in Fire Investigation:
The area exhibiting the most damage was exposed to the fire the longest time; there is more likely to contain the ________.
Seek out any indication of __________.
Point of origin
Low burn
281
3 primary issues with landfill recoveries
Compacting of the body and evidence
Heat generated by the landfill
Various hazards present in the landfill
282
What is the most important tool in a landfill recovery?
3-pronged cultivator rake
283
What creates a significant hazard for cadaver dogs in landfill recoveries?
Methane pockets
284
Evidence associated with buried bodies and scattered remains tend to be widely dispersed in the surrounding soil and vegetation. This demands the application of __________________ techniques in an effort to locate and document the evidence and its scene context.
archeological
285
Cases involving buried bodies usually occur in 2 varieties. What are they?
Police are presented with a grave
Police are seeking out a grave
286
___________ detect anomalies in the surface's magnetic field.
Magnetometers
287
___________________________ sends a low frequency signal into the ground that is returned in different ways after encountering different conditions.
Ground Penetrating Radar (GPR)
288
How does infrared thermography work for finding graves?
It reads a difference in the temperature of the gravesite and the surrounding soil
289
With infrared thermography, do graves make a higher or lower heat signature and why?
Lower
Graves create dead space which produces lower heat signatures.
290
What do vapor detectors do?
They detect decomposition gases, primarily methane
291
Vapor detectors are best employed when the temperature is ___________________ and used in conjunction with a _____________________.
Greater than 45 F
Probing technique
292
Probes are used to detect ______________________________________________________ and are made of 3/8in stainless steel and are generally _______ in length
Difference in the compaction of regular soil and disturbed soil
40in
293
With the probing technique, probes are inserted every _____________ in a horizontal pattern in front of the searcher, a pattern developed from ___________________________.
10-15in
Avalanche search techniques
294
How should ground plants be removed from the surface on top a grave?
Cut, never pulled. If a forensic botanist requires the root, roots have to excavated carefully
295
Why are screens used at a gravesite and what is the suggested method?
To search for small items like small bones, teeth, bullets, etc
2 screening method, one screen is 1/4in mesh and the 2nd is 1/16in mesh
296
Stratification/Superposition is the archeological concept used with gravesite excavation. Each obvious layer of significant artifact encountered is removed __________ order to its deposition.
Reverse
297
How much dirt is removed at a time to prevent disruption of stratification?
2in layers
298
To prevent more trauma to the body, it is recommended to use what tools?
Plastic utensils or bamboo sticks
299
What evidence could be found under the body at the bottom of the grave?
Tool marks, shoe marks, other objects thrown in before the body
300
What can cause dispersal of remains?
Animals
Erosion
Flooding
301
What is the first step when discovering remains?
Verify if the remains are human
302
What search pattern is best for scattered remains?
Line search
303
What are the types of insects found around graves or decomposing remains?
Species attracted to carrion (flies)
Predator species that eat carrion species (beetles)
Omnivorous species that eat any food (ants/wasps)
304
Life stages of flies and bodies
Flies attracted to body
Flies lay eggs on body
Maggots hatch from eggs and eat body
Maggots go through 4 larval stages
Maggots leave body and change into pupae
Flies emerge of pupae and cycle restarts
305
How should live maggot samples be packaged and why?
Container with moisture and food source
To prevent cannibalism
306
At minimum, ________ live larvae should be collected.
20-30
307
Where are beetles often located?
In the soil beneath the corpse
308
Where should soil samples be collected with dealing with buried bodies?
Under the body
From distances approximately 3ft around the corpse
309
What observations is presumptive death determined?
Evident trauma inconsistent with life
Absence of life signs
310
What are normal life signs? (7)
Heartbeat
Pulse in major arteries
Respiration
Evident body heat
Pupils constricting in response to light
Flushing of nail beds
Ability to react to stimuli
311
Early Post Mortem Indicators
Livor mortis
Algor mortis
Rigor mortis
312
Later Post Mortem Indicators
Decomposition
Entomological activity
Mummification
Adipocere formation
Skeletonization
313
______________ is the settling of blood due to gravity
Livor mortis
314
___________ is the stiffening of muscles in the body
Rigor mortis
315
Rigor mortis first appears ________ after death; it is at its greatest ___________ after death. Rigor mortis disappears ________ after death.
2 hours
8-12 hours
24-48 hours
316
What is algor mortis and how is it determined?
Loss of body heat
Core temperature reading of liver
317
___________ involves the physical putrefaction of the tissue due to bacteria
Decomposition
318
Where should clothing be cut at?
At the seams if no defects, patterns, or evidence are present
319
General features of a body
Sex
Race
Complexion
Approximate age
Height and weight
Hair
Eye color
Prosthetics
Clothing
Scars and tattoos
Jewelry
320
Specific features of a body
Physical position and orientation
Post mortem indicators
Wounds
Defects
Bloodstains
Exudates from the body
321
Photographs of the body to be taken
Face identification photos
External condition before clothing removal and cleaning
External condition with clothing removed and before cleaning
External condition unclothed and cleaned
All injuries and abnormalities
Any evidence discovered
322
Primary mechanisms of injuries
_____________ trauma: resulting from lack of oxygen
_____________ trauma: the cutting of tissue
_____________ trauma: the crushing and tearing of tissue
_____________ trauma: produced by a projectile from a firearm
Asphyxial
Sharp force
Blunt force
Gunshot
323
In ligatures aka garroting, furrow marks are __________ the voice box and have _________ height
In hanging, the furrow mark is produced __________ the voice box and create a __________
at or below
even
above
V-shape
324
Autoerotic strangluation deaths are considered _______ deaths and are __________.
hanging
accidental
325
How do choking deaths occur?
foreign bodies like food, dentures, or gags create blockage of airway
326
Difference between choking and smothering
Choking is blockage of the airway
Smothering covers nose and mouth
327
In _________ deaths, the typical mechanism of injury is cerebral anorexia
drowning
328
In positional/mechanical asphyxia deaths, the mechanism of death is cerebral ______. The primary physical effect is ________.
hypoxia
red or purple face and neck
329
Primary forms of sharp force trauma
__________: longer than deep
__________: deeper than long
Incised
Stab
330
In many deaths, ___________________ occurs in the sclerae and conjunctivae
petechial hemorrhaging
331
Blunt Force Injuries
____________: aka bruises, result from damage to blood vessels in or around the injury
____________: only involved upper layers of skin, scraped away
____________: physical tearing of the skin
Contusions
Abrasions
Lacerations
332
What is tissue bridging?
small strands of connective tissue, skin, or nerves that did not tear from the force
333
Chopping injuries are more like ________ wounds with the characteristics of a _____________. Caused by edged weapons.
Incised
Laceration
334
What is stippling?
A condition in which unburned and burned powder is driven into the skin
335
Entry wounds from bullets tend to be symmetrical with an ______________.
Abrasion ring
336
Heat creates this pose/stance. It is where the muscles and tendons shrink, causing appendages and the neck to bend, appearing like the fetal position.
Pugilistic stance
337
Venues of Crime Scene Analysis
The Crime Lab
The Application of the Crime Scene
338
Evidence comes in two forms. What are they?
Physical
Testimonial
339
______________ is "the use of scientific methods, physical evidence, deductive and inductive reasonings, and their interrelationships to gain explicit knowledge of the series of events that surround the commission of the crime."
Crime Scene Analysis
340
__________, the father of modern crime scene investigation, spoke of the necessity of reconstructing crime through the meticulous examination and collection of facts
Hans Gross
341
In 1933, ________ wrote "Scientific Murder Investigation"
Luke May
342
_____________ is one of the first investigative authors to set out a specific crime scene analysis methodology.
Edward Heinrich
343
5 major principles of crime scene analysis
Causal connection
Superposition
Continuity
Chronology
Relationship
344
Superpostion/Stratification
Geologic strata are deposited in a time order, oldest to youngest unless otherwise disturbed
345
The ______________ is the basis of crime scene reconstruction
scientific method
346
The scientific method steps (6)
1. Problem
2. Hypothesis
3. Data
4. Expect (predict)
5. Test
6. Conclusion
347
Crime Scene Reconstruction Steps (7)
1. Collect data, establish key events
2. Establish actions/event segments from available data
3. Define associated actions
4. Order and sequence associated actions
5. Audit the information
6. Determine and final-order the events
7. Final Flowchart overall incident based on event and event-segment sequence
348
___________ Chronology: related to timing aspects
___________ Chronology: sequencing of actions in relation to one another
Absolute
Relative
349
terminus ____ quem: action that preceded another action
terminus ____ quem: action that followed another action
terminus ____ quem: action that occured simultaneously with another action
ante
post
peri
350
__________ is the process of looking beyond the obvious to try and validate or refute previous conclusions
Auditing
351
Risk Management 4 Basic Tentents
Begin managing risk in the planning stages of an event
Accept no unnecessary risk
Make risk-management decisions at the right level
Accept risks only when the benefits outweigh the cost
352
Steps to Accomplish Risk Management (4)
1. Hazard identification
2. Risk assessment
3. Risk control and mitigation
4. Supervision of controls
353
Risk management almost always fails at what step?
Supervision/supervisors
CRIME SCENE INVESTIGATION
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