ROLE OF FORENSIC SCIENCE LABORATORY IN CRIMES

1. 1

2. ROLE OF FORENSIC
SCIENCE LABORATORY
IN CRIMES
2

3. CONTENTS
 INTRODUCTION
 FUNCTIONS & STRUCTURE
 F.S.L UNITS
 INCLUSIONS
 PRINCIPLES
 EVIDENCE
 ILLUSTRATION OF USE OF
F.S.L IN INVESTIGATIONS
 FSL SERVICES & LOCATIONS
 DISCUSSION
 CONCLUSION
3

4. What is Forensic Science?
• Application of scientific knowledge to
aid in the administration of justice
• Study and application of scientific
examination and evaluation of
evidence for legal purpose (criminal
and civil) “science in the service of
law”.
• A special discipline (also called
Criminalistics) that is used to discover
the facts about what happened during
a crime.
• Includes providing timely, accurate,
and thorough information to all levels
of decision makers in our justice
system.
4

5. Functions of FSL
• Examine, compare & evaluate physical evidence so
as to link a suspect to the victim or to the scene of
a crime.
• Protection of innocent (e.g. person who is
suspected and arrested due to circumstantial
evidence is set free, when real culprit is identified)
• Training of police investigators as what constitutes
physical evidence, how it is to be found, collected,
preserved and delivered to the laboratory
5

6. STRUCTURE OF F.S.L
6
.
• DIRECTOR
.
• DEPUTY DIRECTOR
.
• ASSISTANT DIRECTOR
.
• SCIENTIFIC OFFICER
.
• TECHNICIANS

7. FSL UNITS
STANDARD OPTIONAL
Physical Science Toxicology
Biology Fingerprints
Firearms Polygraph
Documents Voice Print
Photography Evidence
7

8. F.S.L INCLUSIONS:
1. Forensic Medicine
(Forensic Pathology & Forensic Psychiatry)
1. Forensic Immunology
2. Forensic Entomology
3. Forensic Toxicology
4. Forensic Odontology
5. Forensic Anthropology
6. Forensic Police sciences (Criminalistics, Questioned
documents, Trace evidence, Ballistics)
7. Other specialities ( Voice print examination, Polygraph,
Fingerprinting, Cyber forensic)
8

9.  Forensic Pathology
Concentrate closely on the understanding of types and causation of
injuries and causes of sudden and unnatural death
Deals with the different stages of death
• Rigor mortis- Stiffening of the body (occurs within first 24 hours)
• Livor mortis- Settling of blood closest to the ground (occurs up to 12 hours)
• Algor mortis- Post mortem cooling (6-12 hours)
9

10.  Forensic Psychiatry
Work with courts in evaluating an individual's competency to stand trial,
defenses based on mental diseases or defects (e.g., the "insanity" defense
and sentencing recommendations).
 Forensic Immunology
Includes DNA fingerprinting & analysis
 Forensic Entomology
It is the study of insects and their relation to a criminal investigation,
commonly used to establish the time of death.
 Forensic Toxicology
Deals with the medical and legal aspect of the harmful effects of toxins &
chemicals on human beings.
10

11.  Forensic Odontology
Evaluates teeth to determine the identification of the deceased
 Forensic Anthropology
Concentrates on the identification of deceased individuals whose remains
are decomposed, burned, mutilated or otherwise unrecognizable
 Forensic Police Sciences
• Criminalistics : EvidenceS such as blood stains, glass, soil, clothing and
firearms is compared, identified, individualised and interpreted.
• Questioned documents examination : Scientific examination of
handwriting, typewriting, printing, ink, paper etc
• Trace evidence : Physical evidence that is found in small but measurable
amounts, such as strands of hair, fibers, or skin cells.
• Ballistics : Characteristics of ammunition, firearms and residue are
examined to find matches between suspects and the evidence found at a
crime scene
11

12. Principles of Forensic science
• Law of individuality
Every object, natural or man made, has an
individuality which is not duplicated in any
other object
• Law of probability
Conclusion from stated premises &
Deriving general principles from facts or
instances.
• Law of progressive change
Everything changes with the passage of
time.
12

13. • Principle of comparison
Only the likes can be compared
• Principle of analysis
The analysis can be no better than the
sample itself
• Facts do not lie
‘Facts do not lie, men can and they do’
facts can also be created’ !
• Locard’s principle (Principle of exchange)
When 2 objects come in contact, there is
always exchange of materials. 13

14. Locard’s Exchange
Principle
“Every Contact Leaves a Trace”
 The value of trace (or contact) forensic
evidence was first recognized by
Edmund Locard (1877-1966) in 1910.
 He was the director of the very first crime
laboratory in existence, located in Lyon, France.
14

15. Evidence
“You can observe a lot by just
watching.”
-Yogi Berra
•
15

16. What is evidence?
• Any item or information gathered at
the scene of a crime, or at related
locations which tends to either
disapprove or establish something.
• Any tangible material that can be
used to prove the facts of a matter in
a court of law.
16

17. TYPES OF EVIDENCE
A.Physical
B.Chemical
C.Biological
D.Miscellaneous
17

18. Physical Evidence
18

19. A. PHYSICAL EVIDENCE
• “Wherever he steps, whatever he touches,
whatever he leaves even unconsciously, will serve
as silent witness against him. Not only his
fingerprints or his footprints, but his hair, the
fibers from his clothes, the glass he breaks, the tool
marks he leaves, the paint he scratches, the blood
or semen he deposits or collects -- all of these and
more bear mute witness against him."
19

20. COMMON EXAMPLES OF
PHYSICAL EVIDENCE
Drug and toxic
substance
Resins, plastics Fingerprints
Paints Explosive residues Hair
Gun shot residues
(GSR)
Serial numbers Tissues
Firearms and
ammunition
Documents Pollen
Impressions Fibers Wood material
Rubber material Soil Feathers
Blood and other body
fluids
Glass Bones
Tool marks 20

21. IMPORTANCE OF PHYSICAL EVIDENCE
• Proves crime has been committed
Eg- Gasoline at a scene of a fire
• Back ups witness testimony or disprove it
Eg-Test blood stains of suspects
• Links suspect with victim or crime scene
Eg-Broken glass of headlight in cuff of suspects pants at scene of
hit and run
• Determines identity of people associated with crime
Eg-Fingerprints, DNA
• Allow investigators to reconstruct a crime
Eg-Blood spatter patterns
21

22. TYPES OF PHYSICAL
EVIDENCE
1. Trace Evidence
2. Transient Evidence
3. Conditional Evidence
4. Indirect Evidence
5. Circumstantial Evidence
6. Individual Evidence
7. Class Evidence
22

23. TRACE EVIDENCE
 Hair
 Fibers
 Glass
 Soil
 Plants
 Minerals
23

24. TRANSIENT EVIDENCE
– Temporary evidence
– Can be easily changed or lost
– Usually observed by first
officer on scene and must be
recorded at that time itself
• Examples?
– Odours
• Perfume, cigarette smoke,
gas
– Temperature
• Coffee pot, car hood, water
in bath tub, dead body
– Imprints
• Footprints in sand,
fingerprints in dust, teeth
marks in perishable food
24

25. CONDITIONAL EVIDENCE
• Produced by a specific
action or event at the scene
• Must be observed and
recorded
• Examples
– Lights
– Doors
– Windows
– Position of furniture
etc…
25

26. INDIRECT EVIDENCE
• Evidence that does not prove or disprove a fact in question
• Provides only a basis for inference about a disputed fact.
• May prove something like the possession of controlled
substances or driving under the influence.
26

27. CIRCUMSTANTIAL EVIDENCE
• Evidence based on suggestion rather than personal
knowledge.
• Implies a fact or event without actually proving it.
• More circumstantial evidence , the greater it weighs.
• Example :
– Blonde hair found in hand of murder victim with black hair & Size
10 sneaker print near the body
– Both of these limit the pool of suspects
27

28. INDIVIDUAL EVIDENCE
• Material that can be
related to a single source
• Narrows an identity to a
single person or thing.
• Examples
– DNA
– Fingerprints
– Handwriting
– Some physical
evidence
• Piece of glass
that fits another
piece like a
jigsaw puzzle
28

29. CLASS EVIDENCE
• Material that can be associated with a group of items that share
properties or characteristics
• Object is similar to group of similar objects but not one single
object
• Narrows an identity to group of persons or things
• Examples
– Blue jeans as evidence
• We can use some individualization such as length, style,
brand, shade but there are still thousands of them.
29

30. B.CHEMICAL EVIDENCE
• Substances that do change their chemical nature can be
observed when their chemical composition is altered
• Only observed during a chemical reaction
• Observed when one substance reacts with another
30

31. – Signs of a chemical change
• Formation of gas (bubbles)
• pH change
• Change of color (indicator)
• Formation of precipitate
• Change of smell
– Examples
• Digestion
• Respiration
• Combustion
• Decomposition
31

32. TESTS TO PROVE CHEMICAL EVIDENCES
• FPN Test- Phenothiazines (Pink- Blue)
• Forrest test – Imipramine (Yellow-green)
• Fujiwara test- Chloroform,Trichloroethylene
• Dichromate test- Ethanol
• Ferricyanide test- Ferrous compounds
32

33. C.BIOLOGICAL EVIDENCE
• Study of the investigation of a living or
dead matter, in reference to its origin,
behaviour and classification.
• Here Applies the knowledge of
biological sciences in order to
investigate blood samples, body fluids,
hair and fibre samples.
33

34. D.MISCELLANEOUS
Some of the examples given for miscellaneous evidence are give
below
 Laundry marks
 Voice analysis
 Polygraph
 Photography
 Stress evaluation
 Narcoanalysis
34

35. ILLUSTRATION OF USE OF F.S.L
IN INVESTIGATIONS
35

36. PAINT
• Physical and chemical analysis of paint evidence (chips or residue)
 Indicates it --class, such as automobile paint, house paint, nail polish, etc.
Can be compared to 40,000 different types of paint classified in a database,
which can be used to identify a particular make or model of car or brand of
tool.
• Paint evidence can also indicate individual characteristics if an
investigator is able to find similarities between two samples, such as the
colour
 number of layers
 chemical composition, or a
physical match between the edges of two paint chips – one from a tool
and one from a crime scene.
Paint Layers
Physical Match of
Paint Chip EdgesPaint Transfer on a Car
36

37. The pattern of cracks in a
windshield fracture can reveal
information about speed, occupant
position, and angle of impact.
Magnified image of glass fragments
GLASS
• Glass particles can be found at various crime scenes, such as breaking
and entering, hit and run, vandalism, or murder.
• Glass at a crime scene is analyzed to determine its color, surface
characteristics, tint, thickness, density, chemical composition, and
refractive index (RI).
• The results of the tests provide clues about the crime and help
investigators connect the evidence to a suspect or other object used in a
crime, such as matching glass from a crime scene to a headlight to a
suspect’s car.
37

38. METALS
• Evidence which are metallic nature is in the form of tools and weaopons .
•EXAMPLES
Wood, metal pieces from the tool used by the criminal may be found at
the scene of the crime and metals fragments from the door and
window fittings.
Could be recovered from the criminals clothing or tool.
38

39. VEGETABLE MATERIAL
• Algae and fungi are usually found on damp walls, in buildings, soils on
vegetation and on domestic articles.
• Drowning death leaves algae residues in the water found in lungs.
• Examples:
The burglar climbing the damp wall or fall-pipe may get smears of
green algae.
Grass fragments, pollen, weeds and seeds are identifiable with their
particular source of orgin.
39

40. EXPLOSIVES
• Explosive substances can be examined to determine its chemical
composition to identify the type of explosive used and its origin.
• Traces of explosives found on a suspect’s clothing, skin, hair, or other
objects may be matched to explosives from the crime scene.
• Materials used to make an explosive device will be compared to evidence
found in the suspect’s possession to confirm a match.
40

41. BALLISTICS
• Characteristics of ammunition, firearms and residue are examined to
find matches between suspects and the evidence found at a crime scene.
• Chemical tests can reveal gunshot residue (GSR) on the hands, face or
clothing of a victim or suspect to indicate how close a person was to a fired
gun.
• Rifling (grooves) in a gun barrel causes distinctive grooves, indentations
and scratches upon fired bullets, which can be matched to the weapon
that fired them.
• Police are able to search the National Integrated Ballistics Identification
System (NIBIS) database to compare markings from bullets, cartridge
cases and shotgun shells to ballistic evidence.
Investigators can compare the
striations on bullets to see if
they match.
41

42. FRAGMENT MATCHES
• When an object broken, torn, or cut, two unique edges are formed, which
are referred to as fragment lines.
• These edges can be compared by the naked eye or with microscopes to see
if they fit together , which indicates that they may have been part of the
same object at one time.
• Investigators may compare the edges on pieces of tape, glass fragments,
paint chips, pieces of a car from an accident, paper bag, etc. to find
possible matches.
42

43. SHOE PRINTS & TYRE TRACKS (IMPRESSION EVIDENCE)
• Impression evidence can be photographed, lifted with tape, or cast with
plaster to compare to a suspect’s shoes or tyres.
• Investigators will examine the evidence to identify the brand of shoe or
tyre based on its thread pattern and other physical features to provide
leads in the case.
• Shoes and tyres will also show wear patterns after being used for a period
of time as well as other features (scratches, nicks, and cuts) that can be
used to match evidence to specific items.
• Example : shoeprints can be matched to a suspect based on how the
threads on the shoes that are worn down due to that person’s walking
style.
43

44. 44

45. TOOL MARKS
• Tiny nicks and chips form on the edges of a tool as it is used, which
can be used to identify matches between evidence and suspects.
• Tools may also pick up traces of blood or other substances that can be
tested or have fingerprints that can be lifted.
45

46. CLOTHES & POISON
• Fibres, paint, grease or dust may be found on the suspects clothes in
a burglary and stains of semen or blood on the clothes of both the
victim and the assailant in sexual offence.
• In a suspected case of poisoning, the identification of the poison is
necessary.
• It must be remembered that the presence of injuries or a disease
sufficient to account for death does not rule out the possibility of
poisoning.
46

47. HAIRS & FIBRES
• Hairs and fibres may be transferred from the suspect or the suspect’s
clothes to the victims’ and vice versa. For example, a suspect may pick up
carpet fibres on his shoes or leave hairs behind at a crime scene.
• Hairs can be examined to identify their origin, such as human or
animal. Hairs with roots intact can be tested for DNA.
• Fibres are used to make clothing, carpeting, furniture, beds, and
blankets. They may be natural fibres from plants or animals or synthetic
fibres that are man-made.
47

48. DUST & DIRT
• Dust, dirt or sand evidence can reveal where a person has traveled and
may be picked up at a crime scene or left behind.
• Investigators examine the samples for chemical composition, pollen,
plant material and other organic matter to find links to a specific crime
scene.
Microscopic Image of Sand 48

49. BODY FLUIDS
• Chemicals and ultra violet light can be used at a crime scene to find
body fluid evidence (Blood, semen, saliva, sweat, and urine)
• Areas with potential evidence are swabbed, bagged and collected in
vials, which are air tight and have a low risk of cross contamination.
Examples:
 Vomit and urine can be used to test for alcohol, drugs, and poisons.
 Cigarette butts may contain dried saliva.
 Semen containing sperm is valuable for DNA analysis.
 Blood can provide DNA evidence and blood spatter can provide clues
about the crime.
49

50. DNA ANALYSIS
• Investigators can extract DNA from almost any tissue, including hair,
fingernails, bones, teeth and body fluids. The DNA is used to create a
profile that can be compared to profiles from suspects or victims.
• CODIS (Combined DNA Index System) is a database maintained by the
FBI that is used to find matches to unknown DNA samples from a crime
scene.
50

51. FINGERPRINTS ANALYSIS
• There are 3 types of fingerprint patterns:
Arches  Loops Whorls
• 3 types of fingerprints recovered from a crime scene
 Patent/Visible- Visible through naked eye.
Plastic- Collected from soaps, wax, gum etc.
Latent- Retrieved only with the help of chemical
reagents. Eg: from door locks, handles etc
51

52. 52
• Investigators also identify unique ridge characteristics in a
fingerprint that can be used to identify a suspect or victim.
• AFIS (Automated Fingerprint Identification System) is a
database used by investigators at local, state and national
levels to search for matches to fingerprints found at a
crime scene.

53. WOUNDS ANALYSIS
• Wounds can often be matched
to weapons or tool marks on the
weapon. Investigators may also
be able to determine the
weapon's size, shape, and length.
• Analysis of a wound may
provides clues to a victim’s
injuries, characteristics of the
suspect (left-handed, right-
handed, height, etc.), and
positions of the victim and
suspect at the time of the
incident. 53

54. FIREARM
• Analyze firearms, discharged bullets, cartridge
cases, shotgun shells, unusual or homemade
weapons, and ammunition components.
• Determines what kind of weapon fired a bullet,
match bullets to specific weapons, and determine
the trajectory and distance of a shot.
54

55. STRING AND ROPE
The criminal may have brought his tools to the scene
of tied up in a bundle with string or cord, and may
have left it behind . If it is identical in structure, size,
shape and appearance with another found in the
suspects possession ,it is of great value
55

56. SKELETAL REMAINS
• Forensic anthropologists analyze skeletal remains to determine four
characteristics for a victim: age, sex, race and stature (height/build).
 Sex - Determined by examining the pelvis, humerus, and
femur
 Age and stature – Determined by analyzing the development of the
teeth, bone growth and the length of specific bones such as femur.
 Race – Determined by analyzing the skull for characteristics
that are common among people of different races.
• DNA samples can be collected from bone, teeth, and hair to provide clues
to a person’s identity. Scientists may also be able to gain clues as to a
person’s past, recent injuries or the cause of death based on bone
fractures and other signs of trauma.
56

57. Questioned Document Examination
Scientific examination of handwriting, typewriting, printing, photocopying, or
other mechanical production of written material. Identify ink, paper, or other
document components for authenticity, forgery, or alteration
57

58. PHOTOGRAPHY
In the forensic science photographs are used
• As a means to record what has been observed
• To reveal that cannot be normally seen
• Applies specialized photographic techniques for recording and examining
physical evidence
58

59. FSL SERVICE
• 26 FSL – One in each state capital
• Regional FSL in important districts
• Karnataka – Bangalore, Belgaum, Mysore,
Mangalore & Davanagere
59

60. LOCATIONS-EXPERT INSTITUTIONS
• CFSL Hyderabad - Chemical Sciences
• CFSL Kolkata - Biological Sciences
• CFSL Chandigarh – Physical Sciences
• New Delhi – Fingerprint Analysis
• CFSL Guwahati
• CFSL Bhopal
• CFSL Pune
• These laboratories are under the control of the Directorate of
Forensic Science (DFS) of the Ministry of Home Affairs.
• The laboratory in New Delhi is under the control of the Central
Bureau of Investigation
60

61. • In July, 2012, NICFS*, New Delhi in
collaboration with NCRB has installed a
centralised solution called VERIFINGER &
MEGAMATCHER
• To date;
 More than 1 million criminal records enrolled.
 More than 10,000 criminals have been
identified.
 More than 500 cases has been solved.
*National Institute of Criminology & Forensic Sciences
61

62. DISCUSSION
• Rapid growth of poverty, recession of global economy, and
the unjust behavior of humanity have become the
contributing factors for increased criminal activities.
• These have triggered to continuous trouble to lives of
innocent people and this is where the discipline of forensic
science come in .
• So FSL plays a vital role in uncovering and unsealing
unsolved mysteries in a certain crime scene .
• Thus FSL becomes the gateway to an honest justice system.
It continues to give hope for the people who are seeking
justice and freedom.
62

63. CONCLUSION
“ No crime could be perfect ”
• Criminals always leave some clues at the scene of crime or with the
victim. At the same time they always carry some traces of the crime
with them.
• Forensic science expert collect these clues and examine them at the
forensic science laboratory to confirm linkage between the crime and
the criminal.
So forensic science laboratory is essential in:
• Evaluating physical evidence encountered in different crime cases.
• Giving better, strong and reliable evidence in the court of law.
• Helping the crime administration.
• Acting as a deterrent to possible crimes in future.
• Helping the innocent people.
• Many cases are still remained unsolved where forensic laboratory
couldn’t give any clue. so there should be more research work and
development should be done to solve the unsolved cases.
63

64. REFERENCES
1. Rao Nageshkumar G , Textbook of Forensic Medicine and
Toxicology, 2nd edition, Page No: 119,440,414,153,119,65,
5,395,408,445 & 419
2. Reddy Narayana K S, Textbook of Forensic Medicine and
Toxicology,30th edition, Page No: 78,189,1,439 & 434
3. Bardale Rajesh, Principles of Forensic Medicine and
Toxicology
4. Parikh’s ,Textbook of Medical Jurisprudence, Forensic
Medicine and Toxicology, 6th edition, Page No:
7.1,3.23,1.1,1.2,1.61,2.32,1.2,11.1,6.1,3.1
5. http://www.journals.elsevier.com/forensic-science-
international/
6. http://www.bjs.gov/index.cfm?ty=pbdetail&iid=375
64

65. 65