. Flashcards
(88 cards)
1
Q
Cordage terms that includes
A
- Cable
- Cord
- Linen
- Robe
- String
2
Q
Made from twisted vegetable or synthetic fibers
A
cordage
3
Q
pertains to small lines includes cord, twine , and string
A
Linen
4
Q
Pertains to small tight lines:
A
- Cord
- Twine
- String
5
Q
Heavier lines with 3 or more strands
A
Rope
6
Q
Rope used in
A
- Suicide
- Robbery
7
Q
Fibers combined and straightened by machine
A
Yarn
8
Q
Drawn in parallel position and twisted together
A
Yarn
9
Q
Single yarn of 2 -3 or more yarns twisted together
A
String or Twine
10
Q
Thick String
A
Cord
11
Q
Obtain from the last layer of the plant stem of dicotyledon plants
A
Soft Fibers
12
Q
Soft Fibers are obtained from the last layer of the plant stem of
A
dicotyledon plants
13
Q
Examples of soft fibers
A
-Cotton
-Flax
-Hemp
-Jute
14
Q
Obtained from the structural system of the leaf of monocotyledon plants
A
Hard Fibers
15
Q
Hard fibers are obtained from the structural system of the leaf of
A
monocotyledon plants
16
Q
Examples of natural hard fibers
A
- Manila Hemp/ Abaca
-Sisal Hemp
-Coir
-New Zealand Hemp
17
Q
Characteristic of Synthetic Fibers
A
- Strong and lighter
- More Flexible
- Greater resistance to chemical damage
- Do not rot
18
Q
Examples of Synthetic FIbers
A
- Nylon
- Polyester
- Polypropylene
- Aramid
19
Q
-Used in Parachute and glider rope.
-3x stringer than Manila Hemp
- Greater elasticity (anchor lines)
A
Nylon
20
Q
Best rope for general use
A
Polyester
21
Q
Polyester resist:
A
- Abrasion
- Sun’s UV
22
Q
50% stronger than manila hemp
resistant to abrasion and UV from sun
A
Polypropylene
23
Q
High melting point and resist stretching
A
Aramid
24
Q
Jute comes from
A
Cochorus plants
25
From cochorus plants
98% produced by Pakistan & India
Blended with high fiber
Jute
26
2nd most important soft fiber
Hemp
27
A seed hair
Not deprived from barks of dicotyledon plants
Cotton
28
Most widely used in rope
Form leaf stem of abaca
Great strength and resistance to wind, sun, and rain
Manila Hemp / Abaca
29
-80% of the strength of abaca
- come from plant Agave sisalana
- Salt water resistant
- Tanzania, Kenya, Indonesia , Brazil, Haiti
Uses in rope twine for sacking soil and cable insulator
Sisal
30
Cordage Fiber Examination
I. Macroscopic
1. Length & diameter with Vernier Caliper
2. General Appearance
3. Stains, debris, direction of projecting surface fiber
4. Free ends
5. Knots
6. Adhering debris
31
Fiber Chemical Test may use of
1. Phloroglucine
2. Aniline Sulfate
3. Iodine & Sulfuric Acid
32
is a representation of an impression made on a soil surface.
Moulage
33
A cast in Plaster of Paris or
other similar material of an object or its impressed outlines on a surface.
Moulage
34
Moulage several
importance:
a. Produce representation of an object
b. Great value in scientific criminal investigation
c. Create mold which photography may not become viable
35
any materials which can be changed from a plastic or liquid state to the
solid state
Casting Materials
36
The following are criteria for a good casting material
a. Must be fluid
b. Must harden rapidly
c. Must not be deformable
d. Must be tough
e. Must be easy to apply
f. Must not adhere to the material
g. Must have a fine composition
h. Must not injure the impression
i. Must be obtainable
j. Must be cheap
37
used for small impressions with a melting point at 60-70
degree Celsius but gives more accurate and detailed impression.
Wood’s Metal
38
A rubbery and gelatinous material which is made up of colloidal Mg soaps.When hot it is thin and pasty, while when cold it is stiff or jelly.
Negocoll
39
Made up of resinous material. Flesh in color and used for external surfaces.
Hominit
40
Brown in color and used to cast the human body
Celerit
41
Holds and keeps casting material from running
Molding Box
42
includes strip of metals, teased ropes and bamboo sticks
Reinforcements
43
used as separating materials
- Shellac and Alcohol
- Talcum powder
44
Casting Chemicals:
NaCl
Borax
Sucrose
NaHCO3
45
is detonated when it is crushed by the force of the firing pin
primer
46
These vapors recondense
into droplets, which are further subjected to high pressure and temperature arising from the
openings as vapors and solidified as particulate that varies in shape and size from submicron to over
100
microns
47
Components of Gunshot Residue
a. Formulation of Primer
b. Formulation of propellent
c. The barrel scrapings
d. The composition of projectile
48
Ammunition primers consists of four basic chemical components:
1. The initiator
2. The oxidizer
3. The Fuel
4. The sensitizing
49
is standard initiator in modern primer
The initiator – Lead styphnate
50
is most commonly used in small arms.
The oxidizer – Barium nitrate
51
Antimony sulfide is commonly used as fuel in primers
The Fuel
52
Commonly used sensitizers are tetracene, pentaerythritol tetranitrate and tetryl
The sensitizing
53
A black powder composed on 75% potassium nitrate, 15% sulfur and 10% charcoal
Gunpowder
54
Combustion product of black powder
Carbonomooxide
carbon dioxide
sulphates
carbonates
thiosulfate
sulphides and potassium
55
Can be single based made up of Nitrocellulose or Double base made up of
Mitrpcellulose and Nitroglycerine
Smokeless Powder
56
Detectable Inorganic components
Lead, Barium, Antimony, Copper from jacket of
bullet, Iron from barrel, Nitrates and nitrite, zinc
and nickel
57
Detectable Organic Components
Nitrocellulose, Nitroglycerine, Diphenylalamine
stabilizer, and DNT
58
The basic principle of trace and transfer evidence is the
Locard Exchange Principle
59
Detection of Gunshot residue
1. Residue should initially be observed and evaluated by the unaided eye and with a low power
stereomicroscope
2. X-ray photography
3. IR-photography-Infra red imaging may be used to visualize heavy soot on dark or bloody
clothing or on multicolored surfaces
4. Chemical methods
60
use 5% nitric acid for inorganic content
Wet Method
61
a technique used to inorganic sample for SEM analysis
Tape lifting
62
Most common technique that makes use of acetone of ethanol as solvents.
63
Most common technique that makes use of acetone of ethanol as solvents.
Swabbing
64
Used for collecting on clothing’s. Clothing debris are vacuumed on to a filter disc. Then using solvents, residue on filter paper will be
collected.
Vacuum lifting
65
Gunshot Residue Methods of Analysis
1. Gross Examination
2. Microscopic Examination
- Paraffin Test
- Walker’s Test
-Griess Test
66
- Non-conclusive
- Use of hand lens
- Check for fine black powder particles:
-Entrance of gunshot
- Dorsum of hand
Gross Examination
67
- Fine particles magnified
- No characteristic shape, color or consistency of gunpowder
Microscopic Examination
68
- Diphenylamine Test
- Dermal Nitrate Test
- Lunge Test/ Gonzales Test
Paraffin Test
69
Uses photographic paper treated with either: C-Acid (2-naphthalamine- 4,8-
disulfonic acid), H- Acid (1-amino-8-naphthol-3,6-disulfonic acid) or Sulfonic Acid
swabbed with alpha naphthalamine in ethyl alcohol
Walker’s Test
69
Uses photographic paper treated with either: C-Acid (2-naphthalamine- 4,8-
disulfonic acid), H- Acid (1-amino-8-naphthol-3,6-disulfonic acid) or Sulfonic Acid
swabbed with alpha naphthalamine in ethyl alcohol
Walker’s Test
70
Principle: Nitrates in the gunpowder residue (NO3) reacts with the diphenylamine
Paraffin Test
71
Principle: Nitrite in acid solution reacts with a primary aromatic amine forming diazonium salt
Griess Test
72
Principle: Nitrite in acid solution reacts with a primary aromatic amine forming diazonium salt
Griess Test
73
Test for Primer components
Sb.,Ba.,Pb.
Swab moistened with 0.1M HCl gathers residues
Harrison & Gilroy Test
74
Ba and Sb converted to isotopes by neutron bombardment
Neutron Activation
Analysis (NAA)
75
High temperature vaporizes metallic elements
Detected through Absorption Spectrophotometry
Flameless Atomic
Absorption
76
Tests for Primer Components
-Harrison & Gilroy Test
-Neutron Activation
Analysis (NAA)
-Flameless Atomic
Absorption
77
Methods of Glass Analysis
- Spectrograph
- X-ray analysis
- Physical properties
- UV Examination
78
The only adequate method for chemical analysis
Not rapid method
Spectrograph
79
Study of diffraction pattern
X-ray analysis
80
Most sensitive method in determining differences
in composition of glass
Physical properties
81
Examined in a dark room A difference in fluorescence
is indicative of physical and chemical differences
UV Examination
82
Glass as evidence in Crime, Forensic chemistry application:
a. Automobile glass in cases of hit and run
b. Broken windows caused by pressure, blow or bullets
83
2 Kinds of Glass Fractures
1. Radial Fractures
2. Concentric Fractures
84
Primary fractures
Resemble spokes of wheel
Radiating outward from the point of impact
Radial Fractures
85
Secondary Fractures
Circles around the point of impact
Connecting to one radiating crack to others
Concentric Fractures
86
When a force pushes on one side of a plane of glass,
the elasticity of glass permits it to bend in the direction of the
force applied. Once the elastic limit is exceeded,
the glass begins to crack.
Breaking of Glass
87
Radial cracks form a Right angle on the Reverse side of the force. Radial cracks are first
commencing on the side of the glass opposite to the destructive force. Stress lines on a concentric crack
will be at right angles to the front. Concentric cracks occur afterwards. Starting on the same side as the
line force.
3 R’s Rule
