This is for my fellow forensic people.........

1. CRIME SCENE
INVESTIGATION
Dr. SUJATHOMAS
JUNIOR RESIDENT (JR2)
DEPARTMENT OF FORENSIC MEDICINE
GMCTHRISSUR

2. •Forensic labs DO NOT solve crime ( they just
analyze the evidence)
INVESTIGATORS SOLVE CRIMES

3. CRIME SCENE
• Place or places, where a particular crime has been committed or
ANY EVIDENCE related to such a crime is found.
Materials can be classified into-
Impression
Biological evidence
Trace evidence
Ballistics &
Documents.

4. PHYSICAL EVIDENCE CRIME SCENE
Encompasses any and all objects that can establish
that a crime has been committed
OR
Any and all objects that can provide a link between
a crime and its victim or a crime and its perpetrator.
Eg., Fingerprints,Tire marks, Footprints, Fibers,
Paint, Building materials, etc.
It is the beginning point for obtaining evidence
which will be used by the crime scene
investigator and the forensic expert.
A thorough investigation of the of the crime
scene is must for proving/ disproving.

5. A CRIME
SCENE
• Crime scenes are never consistent---they are ALWAYS INCONSISTENT.
• Each one presents an investigator with a new challenge.
That is why crime scenes are diversely classified based on various factors.

6. CLASSIFICATION :
• Based on MOTIVE OF CRIME:
• PHYSICAL LOCATION : Indoor
Outdoor
Vehicle
Homicide
Robbery
Sexual assault
Terror attack

7. TYPES OF CRIME SCENE
• Outdoor
• Indoor
• Conveyance

8. WHO`SAT CRIME SCENE…??
• Police officers
• CSI Unit
• Medical examiner
• Specialists

9. CSI
• Collecting
• Preserving
• Documenting &
• Analyzing evidence found at
crime scenes

10. • Long tedious process that involves
• Useful documentation
• Photography or
• Videography of the situation
• Or condition on the scene
• And position of the evidence

11. OBJECTIVES OF CSI :
• Using generally accepted scientific methods,
Locard`s Exchange Principle, and forensic
techniques, CSI can achieve—
• RECOGNITION- Scene survey, documentation,
collection
• IDENTIFICATION- Comparison testing
• INDIVIDUALIZATION-Evaluation & interpretation
• RECONSRUCTION—Reporting & presenting

12. KEY PRINCIPLES INVOLVED IN CSI
• PRINCIPLE OF EXCHANGE (Locard`s Exchange Principle)—
“ whenever two entities come in contact, there is exchange of traces mutually”
PRINCIPLE OF INDIVIDUALITY
“ every object ( natural or manmade) is unique and has an individuality, which is
not duplicated in any other object.”
PRINCIPLE OF PROGRESSIVE CHANGE
“ everything changes with the passage of time.”

13. KEY PRINCIPLES INVOLVED IN CSI
• PRINCIPLE OF COMPARISON :
“ only the likes can be compared.”
PRINCIPLE OF ANALYSIS :
“ the analysis can be no better than the sample on which it is performed.”
PRINCIPLE OF PROBABILITY :
Mathematical concept , which determines the chances of occurrence of any
event in a particular way.
PRINCIPLE OF CIRCUMSTANTIAL FACTS :
“ facts do not lie, men can and do.”

14. 6 BASIC INVESTIGATIVEQUESTIONS
• In the interview, one`s main aim is to
uncover the-
• WHO
• WHAT
• WHERE
• WHEN
• WHY &
• HOW Of the Incident.

15. CORE PRINCIPLES OF CSI
The actions of-
CONTROL
PRESERVE
RECORD
RECOVER &
RECONSTRUCT

16. BASIC STAGES FOR A CSI
(Processing the Crime Scene)
• Approach scene Secure and protect scene
• Initiate preliminary survey/ determine scene boundaries (Record
the scene)
• Evaluate physical evidence possibilities ( Locate & mark the
evidences)
• Prepare narrative description
• Depict scene photographically
• Prepare diagram / sketch of scene
• Conduct detailed search
• Record & collect physical evidence (Collect, pack & label)

17. FIRST STEP IN PROCESSING
A CRIME SCENE
• Secure the Scene
• Separate the Witnesses
• Scan the scene
• See the scene
• Sketch the scene
• Search for Evidence
• Secure and Collect Evidence

18. RESPONSIBILITIES OFTHETEAMSAT
CRIME SCENE
• FIRST RESPONSE TEAM :
• STEP 1 : Initial response at the receipt of any information of a crime
• STEP 2 : Safety first
Assess for any impending danger
Secure the crime scene
Search for any dangerous person
Inform higher ups

19. FIRST RESPONSETEAM :
• STEP 3 : EMERGENCY CARE
Assess for any survival or injured persons
Guide medical team
Identify the physical evidences
STEP 4 : TAKE CONTROL OFTHE SCENE OF CRIME
Identify all the persons in the crime scene
Preventing any unauthorized person from entering into crime scene
Secure and separate all suspects and potential witness
Remove any bystanders or unauthorized persons

20. FIRST RESPONSETEAM :
• STEP 5 : Demarcate the boundaries of the crime scene and protect and secure
Place where crime took place or body of evidence was found
Potential entry & exit points of culprits or suspects
Any sign of movement of victim or the evidences
Use photograph , sketches or videography to document
STEP 6 : Documentation & Handing Over to the Investigation Officer

21. HOW DOYOUWRITEA CRIME SCENE
REPORT ?
• Notes & reports should be done in a
chronological order
• Should include no opinions, no
analysis , or no conclusions
• JUSTTHE FACTS !!!

22. ROLE OF INVESTIGATINGTEAM
• EVALUATE THE CRIME SCENE : Dividing whole area into 3 zones
CORE ZONE : Investigators & rescuers only
BUFFER ZONE : Investigators + Rescuers + Ambulances
PERIPHERAL :To restrict all onlookers

23. TEAM FORMATION
• Can be formed on the basis of type of incident.
• To be selected comprising the experts in that particular field
• Few members invariably in the team :
A trained photographer
One fingerprint expert
Forensic expert for proper evaluation

24. SEARCH FOR EVIDENCE
• Evidence must be collected from the body ( if victim died) by the medical examiner.
• --Evidence needed includes
• Victim`s clothing
• Fingernail scrapings
• Head & pubic hairs
• Blood
• Vaginal, oral and anal swabs (sex crimes)
• Recovered bullets from the body
• Hand swabs from shooting victims

25. LOCATINGTHE EVIDENCE/ Search
• Must be thorough & systematic
-- Must make sure not to overlook any pertinent evidence
-- Failure to do so can lead to accusations of negligence or of covering up the
evidence
Field evidence technician responsible for conducting search for evidence
 May also photograph the crime scene
 Looks for fingerprints, footprints, tool marks, hairs, fibers, etc
 Must also collect possible carriers of trace evidence

26. HOWTO SEARCH FOR EVIDENCE
• Crime scene is usually searched in segments.
• 4 types of search methods are-
• SPIRAL SEARCH METHOD—Search starts at the outer point and gradually moves
toward the center OR starts at the center and gradually moves outside
• GRID METHOD—Crime scene divided into a grid and each grid segment is
searched
• STRIP OR LINE SEARCH—Crime scene divided into strips and each strip is
searched
• QUADRANT OR ZONE SEARCH—Crime scene divided into quadrants and each
quadrant is searched

27. SPIRAL PATTERN

28. GRID PATTERN

29. PARALLEL SEARCH PATTERN

31. RECORDINGTHE CRIME SCENE
• Has only a limited amount of time to
work a crime scene
• - Must photograph the crime scene
• - Must sketch the crime scene
• - Must take notes
• - Must collect , document, label and
package the evidences

32. COLLECTING & PACKAGING
THE EVIDENCES
• Must be handled carefully making sure that exhibit does not get damaged
--If damaged or changed, evidence is not admissible to court
Each item or similar items collected at different locations must be placed in
separate containers
--Prevents damage through contact and prevents cross-contamination
Forceps & other similar tools should be used to pick up small items.

33. COLLECTION OF SAMPLES/EVIDENCE :
• STEP 1 : MAPPINGTHE AREA
An aerial photography or video
Or use sketch to map the area
STEP 2 : DOCUMENTATION
Photographic documentation ( wide angle lens & then a zoom lens)
Proper scale included

34. PHOTOGRAPHY : GENERAL RULES
• The crime scene must not be altered before/ during
photography.
• - Objects must remain where they are until
photographed
• Any proof that the crime scene was compromised
would cause the evidence to not be admissible in
court
• If evidence has been removed or moved, it must be
mentioned in the report

35. PHOTOGRAPHY : GENERAL RULES
• Each crime scene needs to be photographed as
thoroughly as possible
• - All areas where the crime took place should be
photographed at different angles
• - Entries & exits must also be photographed at
different angles
• - It is important to have close-up shots & far-away
shots
• -Evidence should be photographed with a ruler as a
point of reference

36. SKETCHES OF CRIME
SCENE
• Sketches of crime scene are made after
photography.
• Types of sketches are-
-Rough– a draft representation of all essential
info and measurements at a crime scene
- Finished—a precise rendering of the crime
scene
• All sketches are drawn to scale
• All sketches have a legend showing where
certain items are at the crime scene

37. SKETCHES OF CRIME SCENE
• Crime scene sketches must have—
 Title or caption
 Legend of abbreviations
 Symbols
 Numbers of letters used
 Compass designation
 Scale, if drawn to scale
 Documentation block with case number, offense type,
victim`s names, location, date and time, and sketcher`s
name

38. NOTE MAKING OF CRIME SCENE
• Throughout the crime scene processing
time
• Should include—
-- Date & time
-- Arrival information
-- Scene description
--Victim description
-- CSI team members

39. NOTES MAKING----
• Description of the scene
• Location of items of physical evidence recovered with following details—
--Time when an evidence was discovered/ located,
-- By whom,
-- How,
-- By whom it was packaged and marked,
--The disposition of the item after it was collected

40. • STEP 3 : CONTAMINATION CONTROL
Secure the area
Use established routes to access crime scene
Use personal protective equipment (PPE) for self protection
Sample either disposable or single use type
Handle all evidence with care

41. • STEP 4 : COLLECTION OF SAMPLES
• Any evidence that is wet must be air dried before being placed in a container
• Blood-stained evidence should never be stored in an air-tight container
Could cause mould growth which damages the evidence
STEP 5 : PACKING, LABELING & SENDINGTHE SAMPLES

42. COLLECTING & PACKAGINGTHE
EVIDENCES
• Small items may be put in unbreakable plastic bottles with
pressure lids
Suitable for hairs, glass fragments, fibers and other small or
trace evidence
Envelopes are also good containers for evidence
Paper bags are excellent containers for large evidence
Mailing envelopes should NEVER be used to hold evidence.

43. COLLECTING & PACKAGINGTHE
EVIDENCES
• Any evidence is collected and packaged, the container it is in must be marked and
sealed
• Most items should be packaged in a primary container and then placed in a
secondary container
-- Hair is placed in a vial which is then placed inside a paper bag.

44. CHAIN OF CUSTODY
• Is a list of all persons who come in possession of an item of evidence
• Must be established whenever is presented in court
The evidence container must be marked for identification
The collector`s initials should be placed on the seal
If evidence is turned over to another person, the transfer must be recorded

46. CRIME SCENE SAFETY
• GUIDELINES exist to protect investigators at crime scenes
Must wear latex gloves & shoe covers
Must wear masks when potentially infectious dust or mist is at the crime scene
Must be alert to sharp objects
Must maintain red biohazard bag for disposal of contaminated materials
Must not eat, smoke , or drink at the crime scene.

47. RESPONSIBILITIES OF FIRST
RESPONSE & INVESTIGATINGTEAMS
FIRST RESPONSETEAM
• 1) Initial response to crime
• 2) Secure the crime scene
• 3)Take emergency care
• 4)Take control of the crime scene
• 5) Documentation & handling over
to investigating team
INVESTIGATINGTEAM
• 1) Evaluate the crime scene
• 2) Search the area
• 3) Evidence collection
-Mapping
- Documentation
-Contamination control
- Collection & safety of samples
-Packing, Labeling & sending to lab

48. ROLE OF FORENSIC PATHOLOGIST AT
CRIME SCENE
• Provides first hand knowledge of circumstantial evidences
• Minimizes interpretation of facts
• Advice the team to judiciously select & collect biological evidences
• Best opportunity for interaction & liaison between various experts
• CSITeams in India do not have a medical man (forensic pathologist)

49. CRIME SCENE KIT
• Surgical scrubs or aprons
• Gloves
• Shoe covers
• Cap or head cover
• Face shield
• Appropiate PPE depending upon the criminal activity
• Hand lens
• Forceps
• Torch or other lighting arrangement
• Swabs & containers for collecting blood or body fluids
• Containers of different sizes for sample collection

50. DEALING WITHTHE PRESS & PUBLIC
• One of the most difficult tasks
• Avoid talking to the media & public
• In India, considered inappropriate to comment publicly on cases subjudice
• Can inform the public regarding type of case in general, but should not discuss about
the specific findings
• Discussion may be necessary to educate the public.

51. RECOMMENDATIONS
• Visit to the crime scene need to be incorporated in the state`s medico-legal
manual; SHOULD BE INCLUDED AS A DUTY.
• Awareness regarding usefulness of a forensic pathologist in CSI needs to be
augmented.
• Curriculum of undergraduates needs to lay more emphasis on forensic expert`s
contribution to crime scene.Teaching should empower them to handle medico-
legal problems.
• Frequent interaction between law enforcement agencies & forensic pathologists.

52. 5 KEY ELEMENTSOF A SUCCESSFUL
INVESTIGATION :
• Define the scope of the investigation
• Plan the investigation
• Collect the relevant evidence
• Review and analyse the information
• Document the findings
• Summary

53. “GOLDEN RULE” OF CSI/ Management
• “Never touch , change , or alter anything
until it has been documented, identified,
measured, and photographed….
When a body or article has been moved, it
can never be restored to its original position”
“ Use your eyes the most,
Use your hands less, and
Use your mouth the least”

54. CONCLUSION
• CSI is a teamwork
• Successful CSI—Simple, methodical & scientific process
• Properly selected team can give a decisive conclusion
• Presence of forensic pathologist at scene of crime immensely contribute to the
quality of investigation.

55. REFERENCES :
• Recent Advances In Forensic Medicine &Toxicology, Volume 3 –
Gautam Biswas
• Textbook of Forensic Medicine &Toxicology– Anil Aggrawal
• Crime Scene Investigation : A Guide For Law Enforcement
(September 2017)

56. THANK-YOU