Forensic science topic

1. By:
JOHN MICHAEL C. BANTONARE
FORENSIC CHEMISTRY &
TOXICOLOGY

2. FORENSIC CHEMISTRY AS DEFINED:
 Branch of Chemistry
 Chemical principles to solve problems in
administration of justices.
 Application of Chemistry to elucidate legal
problems

3. SCOPE OF FORENSIC CHEMISTRY
 Legal Medicine
 Ballistics
 Questioned Document Examination
 Dactyloscopy
 Photography
 Toxicology

4. FOUR STRATEGIES IN THE PRACTICE OF
FORENSIC CHEMISTRY
1. Collection or perception of specimen to be
examined:
 Sufficiency of samples
 Standard for comparison
 Maintenance of individuality
 Labeling and Sealing
2. Actual Examination
3. Communication of Results of Examination: and
4. Appearance

5. Concerns of Forensic Chemistry
 Blood and blood stains
 Other body fluids
 Gunpowder and
explosives
 Human hair
 Fiber Identification
 Papers and Inks
 Glass structures
 Moulage and casting
 Metallurgy
 Soil
 Arson Investigation
 Drugs
 Poisons

6. BLOOD AND BLOOD STAINS
Significance of this:
1. As circumstantial or corroborative evidence
against or in favor or perpetrator
2. For Disputed Parentage
3. Determination of direction of escape of victim or
assailant
4. Determination of Origin of flow of blood
5. Determination of approximate time crime was
committed.

7. CHARACTERISTICS OF BLOOD
1. Circulating tissue of body
2. 1cc of blood: 5,000,000 red blood cells
3. Man of average size: about 6 quarts of blood (5.68
liters)
4. Made up of:
a. Formed Elements
 RBC (Erythrocytes)
 WBC (Leucocytes) and
 Platelets (Thrombocytes)
b. PLASMA (Liquid portion of blood: composing
about 65% of total blood volume)
5. SERUM – straw-yellowish liquid seen when blood
clots.

8. COMMON PROBLEMS IN THE
STUDYOF BLOOD
A. Where blood has to be searched for.
B. Collection, preservation and transportation of
specimen suspected to contain blood.
C. Does stain contain blood or another substance?
 Preliminary Test
 Confirmatory Test
D. If stain is blood, is it human or animal? Precipitin
Test
E. If stain is human blood, did it come from victim,
accused or from other persons? Blood Grouping

9. PRELIMINARY TEST FOR BLOOD
 Benzidine Test
 Guaiacum Test
 Phenolphthalein Test
 Leucomalachite Green Test
 Hemastix Test
 Luminol Test

10. Preliminary Test
 Presumptive or color Test
 Positive reaction:
 not conclusive stain is blood
 Negative Result:
 conclusive stain is not blood
Reason:
*Other substances yield same reaction as
blood- sputum, nasal secretion, plant juices,
formalin, etc.

11. BENZIDINE TEST:
a. Benzidine solution &Hydrogen peroxide (Agua
Oxigenada ).
b. Positive Reaction: is Blue Color

12. GUAIACUM TEST
a. A.K.A Van Deens, Days or Schonbein’s Test
b. Guaiac &Hydrogen pyroxide
c. Positive Reaction: BLUE COLOR

13. PHENOLPHTHALEIN TEST
a. A.K.A Kastle-Meyer Test
b. Phenolphthalein reagent and Hydrogen
Pyroxide
c. Positive reaction: Red/Pink Color

14. LEUCOMALACHITE GREEN TEST:
a. Leucomalachite Green reagent & Hydrogen
Pyroxide
b. Positive Reaction: Malachite Green with a
Bluish Green or Peacock Blue Color.

15. HEMASTIX TEST
a. Strip moistened with distilled water
b. Positive reaction: Green color.

16. LUMINOL TEST
a. Production of light rather than color.

17. CONFIRMATORY TEST
 Teichmann Test
 Takayana Test
 Wagenhaar Test
 Spectroscopic Examination

18. Confirmatory Test
 Proof of bloodstain:
 presence of characteristic blood pigment,
hemoglobin or one of its derivatives.
 Presence of hemoglobin;
 appearance of Specific Crystals observed
under microscope.

19. Teichmann Test
a. A.K.A Haemin Crystal Test
b. Positive Result:
*Dark brown RHOMBIC CRYSTALS OF
HAEMIN OR HAEMATIN CHLORIDE (arranged
singly or in clusters).

20. Takayama Test
a. A.K.A HAEMOCHROMOGEN CRYSTAL TEST
b. Positive Result:
*LARGE RHOMBIC CRYSTALS OF A
SALMON-PINK COLOR (arranged in clusters,
sheaves and other forms appear within one to
six minutes).

21. Wagenhaar Test
a. Acetone-Haematin Test
b. Small dark, circular crystals.

22. Spectroscopic Examination
a. Most delicate and reliable test for presence of
blood
b. Uses MICROSPECTROSCOPE:
*direct vision spectroscope that fits into
microscope tube in place of eyepiece.
c. Positive Results:
*OXYHAEMOGLOBIN for recent bloodstain;
*METHAHEMOGLOBIN (converted
oxyhaemoglobin owing to exposure to air &
light) in old blood stains.

23. Preciptin Test
 A.K.A HUMAN ANTISERUM TEST
 Human Blood: Formation of gray precipitation
ring at interface of two layers within 20 minutes

24. Blood Grouping
A-B-O System
 discovered by Karl Landsteiner in early 1900’s
 First system of blood grouping

25. SUMMARY OF COMMON BLOOD
GROUP SYSTEM

26. OTHER BODILY FLUIDS
1. Semen
2. Saliva
3. Urine
4. Vaginal Fluids
Note:
*Possible to determine blood group if
individual is a secretor

27. SEMEN
 Fluid produced by male sex
organ
 White to yellowish in color
 It is consist of two (2) parts:
 Seminal Plasma or fluid
 Spermatozoa or sperm cells
 1 milliliter of semen:
 70,000,000 to 150,000,000
sperm cells per:

28. SPERM CELL
 During deterioration
bacteria attacks first
tail, making
identification difficult.
 Flavins
 Yellowish color to
semen
 (Semen) fluoresces
under ultra-violet
lights.

29. EXAMINATION OF SEMEN
A. Wet Specimen
 Odor: Alkaline
 Preparation for Microscopic Examination
 Drop of Fluid (of Semen): placed on glass slide, and
 Drop of distilled water: added.
 Cover slip: placed over preparation.
 Specimen: examined under high power objective

30. EXAMINATION OF SEMEN
B. Dried Specimen
1. Physical Examination
a. Grayish-white or yellowish stain
b. Starchy stiffness to cloth
c. Under UV Light: Fluoresces (not specific for
semen).

31. EXAMINATION OF SEMEN
B. Dried Specimen
2. Chemical Examination
a) Florence Test – Dark brown crystals, rhombic or
needle-shaped.
b) Barberio’s Test – Slender yellow-tinted rhomboid
needles with obtuse angles.
c) Acid Phosphate Test – Orange-red pigment

32. Examination of Semen
B. Dried Specimen
3. Microscopic Examination
a. Specific test for semen: identification of
sperm cell under microscope.
b. Difficult because of many factors which
affecting detection of sperm cells:
 Nature of cloth
 Age of stain
 Condition stain was exposed, and
 Handling of specimen

33. INTERPRETATION
 Presence of sperm cells:
stain is semen.
 Absence of sperm cells:
not conclusive stain is not of seminal origin.
Reason:
*These are some conditions which may lead
to non-detection of semen: ASPERMIA and
OLIGOSPERMIA.

34. Aspermia
 Disorder produced by male organ which produces
semen without sperm cells.

35. Oligospermia
 Semen with very few sperm cells

36. GUNPOWDER & EXPLOSIVES
I. Gunpowder
1. Description:
a) A.k.a propellant
b) Primary propulsive force in
cartridge
c) When exploded causes bullet
to move forward towards gun
muzzle.

37. GUNPOWDER & EXPLOSIVES
I. Gunpowder
2. Types:
a. Black Powder
b. Smokeless Powder
c. Semi-smokeless Powder

38. GUNPOWDER & EXPLOSIVES
I. Gunpowder
3. Distance Determination
a. Contact Fire
b. Pressed and Firm Contact Fire
c. Loose Contact or Near Fire
d. Short Range Fire
e. Medium Range Fire
f. Fired More than 60 cm. Distance

39. Contact Fire

40. Pressed & Firm Contact Fire
 On parts of body where bone is
superficial
 Wound Of Entrances: Star-shaped
 Edges Of Wound: Everted
• Areas in Entrance wound:
blackened by burns, tattooing and
smudging, singeing of hair; confined
at site of wound entrance
• Muzzle imprint, barrel impression on
skin
• Radiating fracture
• Fragmentation of skull
• Severe laceration of brain and its
meninges
• Fragments of lead bullet jacket
• Singeing of hair

41. Loose Contact or Near Fire
 Entrance wound: Large circular/oval
 Abrasion collar/ring: Distinct
 Smudging, Burning and Tatooing: Prominent with
singeing of hair
 Muzzle imprint: May be seen
 Blackening or bullet tract
 Carboxyhemoglobin: wound and surrounding
areas.

42. Short Range Fire
 1 to 15 cm. distance
 Edges of wound: Inverted
 Area of burning: Rifle & high powered firearms -
about 6 inches; ordinary handgun – 3 inches
 Smudging due to smoke
 Powder Tatooing: defense ad limited dimension
of spread
 Abrasion ring/collar contact ring

43. Medium Range Fire
 More than 15 cm but less than 60 cm.
 Gunshot wound: Inverted edges &abrasion collar
 Smudging: Present if less than 30 cm distance
 Gunpowder tatooing: lesser identify and wider are
distribution.
 Contact Ring

44. Fired More Than 60 cm Distance
 Gunshot wound: Circular/Oval
 Wound of entrances: No burning, Smudging,
tatooing
 Contact Ring

45. GUNPOWDER & EXPLOSIVES
I. Gunpowder
4. Determining Presence of Gunpowder
a. Gross examination
b. Microscopic examination
c. Chemical Tests

46. Gross Examination
 A.K.A Examination w/ use of hand lens
 Particles: Fine black powder particles of varying
sizes
 Possible Locations:
 Region of gunshot wound of entrance
 On dorsum of hands
 Outer surface of wearing apparel of victim
 Interpretation of Examination: Not conclusive
reason: other foreign particles appear gunpowder
or primer components.

47. Microscopic Examination
 Fine Particles: Magnified
 No characteristic shape, color or consistency of
gunpowder

48. Chemical Tests
 Laboratory Test to Determine Firearm Residues
 Presence of burning, tatooing and smudging:
inference of contact or near distance
 Gradual disappearance of burning and tatooing:
Distance increases
 Appearance of minute particles of burning and
unburned residues and primer constituents
 Dermal Nitrate Test – Not conclusive but
corroborative evidence.

49. HAIR IDENTIFICATION
1. Hair
 Appendage of skin
 Occurs everywhere on human body except on
palms of hand and soles of feet
 Generally long and stiff
 Consists of ROOT, SHAFT & TIP
2. Cuticle
 Outmost covering
 Consists of one layer of non-nucleated polygonal
cells (overlap like scales of fish)
 Free edges of cells are directed toward distal end
of hair.

50. 3. Cortex
 Intermediate and thickest layer of shaft
 Composed of elongated, spindle-shaped fibrils
which cohere
 Contains pigment granules in varying
proportions depending on type of hair
4. Medulla
 Central canal of hair
 Empty or may contain various sorts of cells,
more or less pigmented.

52. 5. Continuous Medulla – found in large number of
animals.
6. Interrupted Medulla – very often in humans ,
monkeys and horses.
7. Micrometer – instrument attached to
microscope and is used to measure diameter of
hair.
8. Medulla Index – ratio of size of medulla to
diameter or shaft.
9. Fuzz – Generally short, fine and this time curly
and wooly.

53. FIBER IDENTIFICATION
Types of Fibers
 Animal – Number of fiber are derived from animal
product most important being wool, silk, camel’s
hair and fur.
 Vegetable – This class includes most of hemp,
ramie and sisal
 Mineral and Synthetics – First provide useful
fibers like glass wool and asbestos which is used
for safe insulation, while latter is applied chemistry
which produced a number of fibers like rayon, nylon
orlon and dacron.

54.  Cotton Fibers – Flattened,
twisted fibers with thickened
edges, Irregularly granulated
cuticle. No transverse
markings .
Fibers show spiral twist.
Fibers swell carbonate
dissolves in ammonia. It is
insoluble in strong sodium
hydroxide but soluble in
strong sulfuric acid and
partially dissolved in hot
strong hydrochloric acid.

55.  Flax Fibers – Apex tapering to
fine point. Transverse sections
are polygonal and show a small
cavity.
The fibers consist of
cellulose and give blue or bluish-
red color when treated with a
weak solution of potassium iodide
saturated in iodine and sulfuric
acid.
The fibers which show
transverse lines and are usually
seen in group formation, dissolve
in a solution composed of copper
sulphate and sodium carbonate
in ammonia.

56.  Hemp Fibers – Fibers
show transverse lines and
consist of cellulose.
Large oval cavities
are seen in transverse
sections. The end is
usually blunt, and there is
often tuft of hair at the
knots.
Stains are bluish-red
with phloroglucin and
yellow with both niline
sulphate and weak
solution of potassium
iodide saturated in iodine
with sulfuric acis.

57.  Jute Fibers – Are quite
smooth without either
longitudinal or transverse
markings.
The fibers have typical
large cavities which are not
uniform but vary with degree
of contraction of the walls of
the fibers which are lignified.
The ends are blunt.
The fiber are stained red
with aniline sulphate, also with
iodine and sulfuric acid.

58.  Wool Fibers – These fibers can easily be
distinguished from vegetable fibers since the
former show an outer layer of flattened cells and
imbricated margins.
The interiors are composed of fibrous tissues
but sometimes the medulla is present.
They do not dissolve in a solution composed
of copper sulphate, sodium carbonate and
ammonia.
Stain is yellow with iodine and sulfuric acid
and also with picric acid. Do not dissolve in
sulfuric acid. Smell of singeing on burning.

59.  Silk Fibers – Manufactured silk is almost
structureless, microscopically.
Fiber’s stain is brown with iodine and sulfuric
acid and yellow with picric acid .
They dissolve slowly in a mixture of copper
sulphate, sodium carbonate and ammonia.

60.  Linen Fibers - Fibers are straight and tapering
to a point.
Cortical are shows transverse lines which
frequently intersects , simulating a jointed
appearance.
The medullary region shows thin dense line.
They do not dissolve in concentrated sulfuric
acid.
If placed in 1%alcoholic solution of fuchsin
and then in a solution of ammonium hydroxide,
they assume a bright red color.

61. EXAMINATION OF PAPER
Examination by Laboratory:
A. Physical Test
1. Thickness, measurement of length and width
2. Weight per unit area
3. Color
4. Finish such as bond, laid smooth or glossy
5. Capacity , opacity of paper for transmission of light
6. Folding endurance as determined by instrumentality
by number of alternate folds paper will stand before
breaking
7. Bursting strength as determined by measurement of
pressure necessary to burst hole in sheet of paper
8. Accelerated aging test performed by means of high
temperatures or strong artificial light

62. EXAMINATION OF PAPER
B. Chemical Test
1. Fiber Composition
2. Absorption
3. Loading Materials and,
4. Sizing

63. Fiber Composition
 Chemical reagents are applied to small sections
of paper to determine nature of constituents of
fibers.

64. Absorption
 Strips of paper are suspended in liquid to
determine either rate of absorption or total
absorption of paper.

65. Loading Materials
 Test is performed by burning and ashing greater
part of ordinary sheet of paper
 Ash is analyzed
 If limited sample of evidence: test not
recommended.

66. Sizing
 By use of few drops of chemical reagent, sizing of
two different specimens of paper can be
compared
 Small perceptible stain results from these tests.

67. WATERMARKS
 The chief characteristics indicating the source or
origin of paper is Watermark.
 It is distinctive mark or design placed in the paper
at the time of its manufacture by passing the
paper under a “DANDY ROLL”.
 Several designs are present on the dandy roll similar
to each other, but bearing individual characteristics,
particularly if the roll has been subjected to wear or
damage.
 By examining the watermarks, the examiner is able to
identify the paper as to the product of a particular
manufacturer.

68. COMPARISON OF INKS
 To determine whether the two documents were
written with the same type of ink various physical
and chemical methods are available.
 The inks are compared visually for color. The
naked eye, color filters and infra –red
photography usually reveal is the most generally
used chemical reagent.
 The reagent may be applied with a sharpened
wooden tooth pick to small area of writing.

69. COMPARISON OF INKS
 When hydrochloric acid is placed on iron nutgall ink,
the color disappears and turns to light blue;
 on logwood ink a red color develops;
 on Nigrosin or carbon ink there is no reaction.
 To distinguish Nigrosin from carbon ink, a 10%
solution of sodium hypochlorite is used.
 It should be noted that these reactions sometimes
take place over a period of hours.
 The investigator should test inks only as a
screening procedure where a number of suspect
documents are available.

70. GLASS FRACTURES
Definition and Composition of Glass:
Glass is best described as super cooled liquid
which possesses high viscosity and hence,
rigidity .
Glass is usually composed of oxides such as
silica (SiO2) boric oxide (B2O3) and phosporus
pentoxide (P2O5).

71. TYPES OF GLASS FRACTURES
 Radial Fracture – Primary fracture resembles the
spoke s of a wheel radiating outward from the
point of impact.
 Concentric Fracture – Secondary fracture
having the appearance of circled around the point
of impact connecting one radiating crack to other,
thus forming triangular pieces of glass.

73. From the study of these two types of fracture s
(impact) it is possible to derive the following:
1. Point of Impact - The front of the glass can be
determined due to the accumulation of dust and
dirt on the glass.

74. 2. Direction of Impact - a bullet will make a clear
cut hole in the side of the entrance rather than
on the exit side.
 If a shot is fired perpendicularly it will give a crater of
uniform cratings , or flakings.
 If the shot is fired at an angle from the right, left exit side
of the glass will give more flakings and vice versa.
Depression will be produced on the exit side on the glass
due to rebound of the glass. Radial fracture can be felt on
the exit side and the concentric fracture on the entrance
side.

75. 3. Cause of Fracture – Fracture due to heat does
not exhibit a define pattern of radial and
concentric fractures but are characteristically
wavy.
They show very little stress lines, whereas
fracture due to mechanical mean show a
definite pattern of radial and concentric
fractures.

76. MOULAGE AND OTHER CASTING
TECHNIQUES
Criteria of a good casting material:
1. Must be readily fluid or plastic when applied .
2. Must Harden rapidly to a rigid mass
3. Must be deformable nor shrink
4. Must be tough
5. Must be easy to apply
6. Must have no tendency to adherence the
impression
7. Should have a fine even composition and surface
8. Should not injure the impression
9. Should be easily obtainable
10. Should be cheap

77. The commonly
used casting material
in the Philippines is
plaster of Paris.
In the U.S.,
Plaster of there are:
Mikrosil, Shoe Print
Wax, Silicon, Bio-
Foam, etc. depending
on the manufacturing
company.

78. Some Technique in Connection
with the used of Plaster of Paris:
1. Hastening – add ½ teaspoonful of table salt to
the plaster.
2. Retarding – add 1 part of a saturated solution
of borax to 10 parts of water be used in making
the plaster. One teasponnfulof sugar also be
used
3. Hardening - soak in sodium bicarbonate

79. CAST OF HUMAN BODY
1. Negocoll – this is a rubbery gelatinous material
made of colloidal and magnesium soaps.
2. Hominit - a flesh colored resinous substance
used for making positives from negocoll
negatives.
3. Celerit – A brown colored substance used for
backing and strengthening the hominit

80. CHEMICAL DEVELOPMENT OF
LATENT FINGERPRINTS
Classification of Crime Scene Prints:
1. Visible Print – A print that results after a finger ,
which has previously touched contaminants as
blood, grease or ink touched a clean surface.
2. Plastic Print – A print that results when a
finger touches a plastic material such as wax,
soap, or dust and creates a negative impression
of its ridge pattern.
3. Invisible Print – Latent Print

81.  Locating visible or plastic prints at the crime
scene normally presents little problem to the
investigator, because these prints are usually
distinct and visible to the eye.
 Latent prints, on the other hand, are difficult to
locate. They can only be seen after the surface
on which they are imprinted has been treated with
powders or chemicals.

82. In developing latent prints:
 the investigator is influenced by the kind of surface that is
being examined in choosing a developing method.
For example:
Prints on porous evidence such as paper , unfinished
wood, cardboard, etc. are normally developed by treatment
with a chemical.
On the other hand, prints on nonporous evidence
such as plastic , glass, metal, foil, etc., are either
developed by powdering method super glue fuming
method.

83. 1. Powdering Method – commonly used materials are
black and gray powder.
2. Iodine Fuming – vapors of iodine and brown in color
differentially absorb into the debris forming the print,
causing the ridge detail to stand out.
3. Silver Nitrate – the process employs 0.2% solution Of
silver nitrate in distilled water that is used to on or
saturate the paper, producing silver chloride only in the
ridge areas. The paper is exposed to light, and the print
turns black.
4. Ninhydrin – develops prints on porous surfaces in
violet color.
5. Super Glue - Develops prints on nonporous surface in
white color.

84. Mettallurgy As Applied To Crime
Detection
Definition:
1. Metallurgy - the art of extracting and working in
metals by the application of chemical and
physical knowledge.
2. Metallography – the branch of metallurgy which
involves the study of the microstructures of
metals and alloys.

85. Application of Mettalurgy in
Criminal Investigation
1. Robbery (with force upon things) – where
entrance is by breaking doors with the use of
metallic tools. Traces of these tools can be
examined under a metallographic microscope.
2. Hit and Run Cases
3. Bomb and Explosion
4. Nail Examination
5. Counterfeit coins
6. Restoration

86. PETROGRAPHY AS APPLIED TO
CRIME DETECTION
Petrography
- is that branch of geology which deals with
the systematic classification and identification of
rocks, rock forming minerals, and soils.
This definition has been construed to cover
not only the study of soils an other mineral
substances, but also dust and dirt, safe
insulations, ceramics and other such materials,
both natural and artificial.

87. SOIL
Soil as evidence:
 Has been overlooked by most investigators
probably because it is such a commonplace
substance is more or less taken for granted.
 Researchers have shown that soils are greatly
diversified and vary considerably over the surface
of the earth, not only from widely separated
points but also from points quite close together.

88. Classification of Soils
1. Alluvial Soil – its particles may be derived from
almost infinite number of sources, and since the
action of water and wind would in a few cases
be identical over long periods of time in different
spots, great variations in composition would be
expected.
2. Colluvial Soil –soil in which some movement
and intermingling of parts has occurred would
be expected to be less variable.
3. Sedentary Soil – least variable

89. Constituents Of Soil
1. Primary Minerals – undecomposed rock
fragments ranging from stones down thru
pebbles, sand, and silt.
2. Clay Minerals – may be found in nearly all soils
and is the major constituent of most heavy
soils. It imparts to a soil cohesiveness and
plasticity, and becomes hard and adherent on
heating
3. Organic Constituents – organic matter is one of
the most variable of all soil constituents and is
of peculiar importance in the identification of
soils.

90. Dust and Dirt
- has been described as “matter in the wrong
place”.
Classification of Dust:
1. Dust deposited from the air
2. Road and footpath dusts
3. Industrial Dusts
4. Occupational Dusts

91. ARSON INVESTIGATION
The technical Aspect of Arson Cases:
 Burning of combustion is the rapid oxidation of
substances accompanied by the generations of heat and
light.
 Burning occurs only when three essential ingredients are
present: FUEL, OXYGEN, & HEAT.
 Obviously, to create a fire three must be present
combustible materials. It may be solid, liquid or gas.
Strictly speaking, only gasses burn. The solids and
liquids must be heated to liberate flammable gases.
 The gases in turn must be raised to the proper
temperature of the fuel to the kindling point.
 Finally, there must be a supply of oxygen since burning
is a process of oxidation. Oxygen may be supplied from
the air or from oxidizing agents.

92.  Without fuel, the elimination or exclusion of
oxygen, or when the heat is sufficiently low
enough is not capable of maintaining the
process of combustion; burning will be
extinguished.

93. The Triangle of Fire
 Fuel , Heat and Oxygen are known as the fire triangle.
 All three must be present in order for them to
produce fire. Solids and liquids do not burn, only
gases burn. It is heat that converts solids and liquids
to flammable gases. In the case of gasoline and other
volatile liquids, the surface of the liquid is constantly
liberating flammable gases. It is only these gases that
burn.
NOTE:
*For burning to continue, there must be the fourth
element, i.e., uninhibited chain reaction.

94. Propagation of Burning
Conduction
 the transmission of heat thru a medium.
 Heat that is conducted is transferred from
molecule to molecule.
For example,
*heat applied to one end of an iron rod
spread throughout the entire rod iron. In a
similar manner, walls and floor may conduct
heat from a burning portion of a building to other
portion and help escalate the fire.

95. Convection –
 a diffusion of heat through a fluid (gas or liquid)
by means of the flow of the hotter parts of the
fluids to the colder parts.
For example
a fire in a corner of a room will heat the air
directly around it. The heated air being lighter
than the cooled air, will rise to the ceiling; the
displaced cooler air will take the place of the
heated air. As this process continues, the heat
from the fire will be facilitated.

96. Radiation –
 the process by which heat is transferred in straight lines from a
source to a receiving materials without heating the intervening
medium.
For example,
*the earth received its heat from the sun by means of
radiation from a burning building to a neighboring building, which
may set fire or search by the intensity of the transferred heat.
*The amount of heat transferred by radiation depends on
the intensity of the transferred heat , or intensity of the burning,
the distance between the burning and receiving surface, and the
angle at which the radiated heat strikes the receiving surface,
and the presence or absence of any obstruction to the straight
lines of radiation .

97. Causes of Fire
A fire may originate intentionally or accidentally. One
method of proving arson is to eliminate systematically the
possibility of accident.
An accidental fire may arise from the working of certain
forces of nature or from negligence in the use of equipment
and materials.
Natural causes of fires are:
1. Sun rays focused by bubbles in window panes, shaving
mirrors by some other peculiarly shaped glass article which
may serve as convex lens.
2. Lightning - Lightning usually strikes a highpoint of the
building and may be traced in path to the ground. Traces of
lightning are melting of metal parts of the building streaked
paint with burned areas, cracks in the walls, broken bricks
and soot driven into rooms from chimney.

98. Additional Information to be obtained thru
observation colors of smokes/fumes and odor
Evolved:
1. White Smoke - indicates burning of humid
materials.
2. Black smoke accompanied by large flame –
indicates petroleum products or rubber .
3. Reddish Brown Smoke – presence of
nitrocellulose sulfur, sulfuric acid, nitric acid
,hydrochloric acid.
4. Red Flame - presence of petroleum
5. Blue Flame – presence of alcohol , aldehyde or
ketone.
6. Biting Smoke - irritating to nose and caused
coughing indicate presence of chlorine.
7. Garlic Odor Smoke – presence of phosphorous

99. Laboratory Test Performed on
Specimen Submitted :
a. Preliminary Test – ashes or debris suspected to
contain inflammable substance is placed on a wide
mouth test tube/glass with fitted rubber stopper and
heated, fumes evolved is tested with SUDAN or
RHODOKRIT powder.
b. If Positive result is obtained from the above-mentioned
test, said sample is subjected to steam distillation. Steam
distillate obtained is injected into the GAS
CHROMATOGRAPH is a highly sophisticated laboratory
instrument used in the identification of gases/accelerant.
c. Spectrographic analysis using QUARTZ
SPECTOGRAPH – is conducted in cases wherein
foreign metals are recovered in the scene of the incident.

100. TOXICOLOGY
 Toxicology - science of poisons: the scientific
study of poison, especially their effects on the
body and their antidotes.
 Poison – Anything other than physical agencies
which s capable of destroying life, either by
chemical action on the tissues of the living body ,
o by physiological action by absorption into the
living system.

101. Site of Action of Poison
1. Local Action - The poison may act on the skin
or on the mucous membrane or on any part of
body where it is applied.
Example: Sulfuric acid
2. Remote Action – The poison may act remote in
any of the following ways :

102. a. By production of shock. Example: Poisoning by
strong acid.
b. By absorption into the blood and being carried
to the organs they effect. Ex.: Morphine is
absorbed by the blood and carried to the brain
and depresses it.
c. By transmission through the nerves of local
parts affected going to the nerve centers and
then reflected to the organs on which they act.

103. Site Of Remote Actions of the Different
Poisons are:
a. On the Brain: Narcotics, alcohol, cerebral stimulants
like caffeine.
b. On the Cord: Strychnine (Poisonous plant product: a
bitter white poisonous alkaloid obtained from nux
vomica and related plants, used as a poison for the
central nervous system. Formula: (C21H22N2O2)
c. On the Peripheral Nerves: Curare (plant resin
causing paralysis a dark resin obtained from certain
South American plants, used by indigenous hunters to
poison their arrows and in medicine as a muscle
relaxant.
d. On the Alimentary Tract: Corrosives

104. e. On the Kidneys: Cantharides(INSECTS European
beetle: A green European blister beetle, used as a
source of the stimulant and irritant cantharides.
Latin name Lytta esicatoria cantharis
vesicatoria. Also called cantharis DRUGS toxic
preparation used as aphrodisiac: a toxic preparation
made from the crushed dried bodies of the Spanish
fly, used in the past as an aphrodisiac and to treat
skin blisters)
f. On the Salivary Gland. Mercury
g. On the Liver. Phosphorus
h. On the Mocous Membrane. Arsenic

105. i. On the Heart Digitalis
j. On the Blood Vessels. Ergot (fungus attacking cereals:
a disease of cereals caused by a parasitic fungus attack
that grows in dense black masses (sclerotia) in the
grains of the ear.
k. Latin name: Claviceps purpurea. Also called
black bread mold. Fungal bodies used in medicine:
the dried sclerotia of an ergot fungus that yield
substances used in drugs to treat migraine and to induce
uterine contractions in childbirth), Nitrites.
l. On the Blood Cells. Snake venom
m. Both Local and Remote. The poison may act at the site
of application and in some distant place. Ex. Carbolic
acid is n irritant to the Circumstances Affecting Action of
Poison.

106. 1. Method of Administration:
Poison may enter the body in the following ways:
a. Orally – Except irritants and corrosives, poisons
must be digested or absorbed in the gastric or intestinal
mucosa before producing effect.
b. Hypodermically – Poison reaches the blood
stream without passing the digestive organs.
This methods is only available for such
substance that are soluble in the lymph and tissue
juices.

107. c. Intramuscularly – Absorption is faster than in
the hypodermic method.
d. Endodermically – The poison may be rubbed
into and absorbed through the skin.
e. By Rectum, Vagina or Bladder – Absorption
through the rectum is about twice as much
as absorption through the mouth.
f. By the Lungs – Poison through this route may be
made of a substance which can be
transformed to gaseous state.

108. 2. Idiosyncrasy: Some persons posses sensitivity
to certain foods or drugs. The most common
drugs are potassium iodide, arsenical
preparations, aspirin and sulfas. As to foods, the
most common are fish, shrimps, eggs and oysters.
3. Age: There are substances which are considered
poison for babies but wholesome for adults, while
the opposite is true for other substances.

109. 4. Habit: The body may acquire tolerance to some
drugs. Habit diminishes the effect of certain
poison. Tobacco, alcohol, opium, barbiturates,
arsenic are good examples of this.
5. Dose: The effect of drugs and poisons in the body is
usually proportional to the dose taken.
Ex. Alcohol, when taken in small dose, stimulate
body reflexes and tone, while large amount
depressed the whole body.
Fatal Dose: This is the smallest dose known to
cause death: not the smallest amount which will
certainly cause death.

110. Treatment of Patient Suffering from
Acute Poisoning
1. Evacuation of the Stomach:
a. A long rubber tube is introduced to the mouth and
allowed to reach the stomach.
 Fluid must first be introduced into the stomach to prevent the tube to
come in close contact with its wall.
 Fluid is withdrawn and introduced until traces of the poison are
removed.
 The procedure is contra - indicated in poisoning by corrosives on
account of the danger of tear or laceration of the stomach wall.

111. b. Administration of Emetics – causing vomiting
or causing a person or animal to vomit.
2. Neutralization of the Poison that Remains in the
Stomach
3. Application of Physiological Antidotes – substance
that counteracts poison: a substance that counteracts
the effect of a poison or toxin.

112. 4. Keep the Patient Alive by General Measures,
While his organs of elimination are getting rid of the
poison. Treat any urgent and dangerous symptoms.
5. Eliminating the Poison: The elimination of the poison
is aided by purgatives, sudorifics, and diuretics.
Sweating may be encouraged by hot bath, warm
packing, and injection with apomorphine.

113. SUDORIFICS – causing production of sweat:
causing the production of sweat.
DIURETICS – causing increased urine output:
causing increased flow of urine.