CRIME SCENE
INVESTIGATION
Unit I
FSC 1803
Dr. Shefali Gola
Crime Scene
• The crime scene is the locale from which the majority of
the physical evidence associated with the crime is
obtained.
• It provides investigators with a starting point for the inquiry.
• To determine the identities of the suspect and victim and
to piece together the circumstances of what happened
during the crime.
• Physical evidence found at the scene can be the key to
the solution of the crime.
• A thorough investigation of the crime scene must be
completed.
Importance
• Crime scene provides information useful to:
– Establish corpus delicti (the fact of a crime having been
actually committed)
– Provide link b/w the criminal, the victim and the scene of
occurrence
– Evaluate the pattern of events
– Help reconstruction
– Provide leads
– Indicate number of culprits, weapons
• Crime scene may be
– A room, a cellar or a roof
– It may be a road or a road side, an open field, a jungle,
hill or a mountain, a stream or a river.
– It may be a pond, a lake or a sea-shore.
– It may be a vehicle: a car, a truck, a bus, a boat, a ship
or an aeroplane.
• Evidence , in criminal investigation, is any item that helps
to establish the facts of a related criminal case.
• Evidence may be found at the scene of the crime or on the
victim or be taken from the suspect or the suspect’s
environment.
Location
• The crime scene is located from the following:
1. Accounts of eye-witnesses
2. Marks of struggle
3. Corpus delicti
4. Abondoned articles, impressions and prints,
bloodstains and stains from other body fluids.
5. Traces carried over from the scene.
Types of Crime Scene
Can be classified by:
Location of Criminal Activity- Primary, secondary
Physical Location of the Crime- Indoor, outdoor and
vehicle
Size of Area- Microscopic, macroscopic
Type of Crime Committed- Burglary, homicide, hit and
run, rape, etc.
Location of Criminal Activity
Primary Crime Scene
• The primary crime scene is an area, place or thing
where the original crime or incident occurred or where
the majority or a high concentration of physical
evidence will be found.
Secondary Crime Scene (subsequent crime scenes)
• Secondary crime scene/s are places or things where
physical evidence relating to the incident may be
found. The potential physical evidence will usually be
transported away from the primary crime scene.
• May include surrounding areas where evidence may
be located
Size of Crime Scene
Macroscopic = one location, composed of many
microscopic crime scenes
Microscopic = focuses on specific type of physical
evidence
Macroscopic = McDonalds Area Microscopic = GSR on Baio’s hand
• Type of Crime Committed
– Homicide, Robbery, Sexual Assault, etc.
Physical Location of Crime Scene
Indoors, Outdoors, Vehicle, etc.
Crime Scene Investigation
Goals are to determine the following
– What happened
– Where did it happen
– When did it happen
– Why did it happen
– Who may have perpetrated these actions
– How was the incident carried out
Information from Scene
1. Linkage of persons, places and things
– Locard Exchange Principle: when two objects come into contact
with one another, an exchange of matter takes place.
– Physical evidence can link suspect, victim, crime scene, and
objects to one another
2. Proving or disproving witness statements
– Can identify intentional lies
– Can identify unintentional eyewitness mistakes
3. Identification of Suspects
– Fingerprints and DNA
4. Identification of Unknown Substances
– Illegal drugs, poison, anthrax
Processing the Crime Scene
Crime Scene Investigation Models
– Requires teamwork by crime scene
personnel and investigators
• Detectives • Lab Scientist
• Patrol Officer • Medical Examiner
• Crime scene tech.
Processing the Crime Scene
1. First Officer on the Scene
2. Securing the Crime Scene
3. Crime Scene Survey
4. Crime Scene Documentation
5. Searching the Crime Scene
6. Collection of Physical Evidence
1. First Officer on the Scene
Safety is the primary concern
Assist the victim
Search for and arrest suspect
Detain and separate witnesses
Protect the crime scene (barrier tape)
Note any changes made to the scene
2. Securing the Crime Scene
Anyone entering the crime scene will deposit and
remove evidence. (Locard Exchange Principle)
Secure the scene with physical barriers
One officer assigned to prevent entrance
of unwanted personnel
3. Crime Scene Survey
After the scene is secure, the investigator and first
responder do a “walk-through”
Prepare an initial reconstruction
Note any temporary evidence
Note points of entry/exit that require attention
Access scene for personnel, precautions, and
equipment needed
4. Crime Scene Documentation
1. Taking Notes of the Crime Scene:
Must be taken throughout processing the crime
• Record activities including:
– Date and time of notification and information received
– Arrival Information
– Scene Description (environment, evidence)
– Victim Description
• Must also include a detailed written description of the scene
with the location of items of physical evidence recovered
– Must also identify the time an evidence was discovered, by
whom, how and by whom it was packaged and marked,
and the disposition of the item after it was collected
• Evidence recovery log: A chronological record of who found
what evidence, where, witnessed by whom, and notations
about other ways the evidence may have been documented,
e.g., photography
Note Taking
• Note taking is important for several reasons.
• It forces investigators to commit observations to
writing and to keep a detailed record of everything
observed and accomplished.
Some general points about notes and note taking
are:
1. Notes should be made as events unfold, and in
chronological order.
2. Notes should detail, step-by-step, all actions.
3. Notes should be complete and thorough.
4. Notes should be clearly and legibly written.
5. Negative or unexpected conditions (the
absence of bloodstains or a light that is found
on) should be noted.
6. The note taker should be as specific as
possible. If an item of evidence is to be
located, a description such as “on the living
room floor, 6 inches east of the west wall and
3 feet south of the north wall” should be used.
Vague statements such as “near” or “to the
left of” should be avoided.
Notes taken at crime scenes should include the following
information:
• Date and time the crime was first reported to the police
• Type of crime
• Location of the crime scene and a description of the area
• Description of the crime or event leading up to the
investigation
• Name of the person who requested the crime scene
investigation
• Names of all officers, witnesses, investigators, and
specialized personnel at the crime scene
• Names of the persons who conducted the crime
scene search and who took photographs and
fingerprints, made sketches, and collected
evidence
• Weather and lighting conditions at the time of the
investigation
• Description of the primary crime scene, including
the location of the body and accompanying details
• Location of any evidence found during the
investigation and the names of those who
collected it, and the results of a search for
fingerprints and other trace evidence
• Description of the location, including the
surrounding houses, streets, and community
• Description of the interior and exterior of the
crime scene, including the type of residence,
number of rooms, and windows
• Description of the outside of the scene
including the terrain, type of plants, soil, etc.
• The date and time the crime scene
investigation was concluded
2. Videotaping the Crime Scene
• Long shots and close-ups
• Narration of events and scenes being videotaped can be
useful for later analysis.
• Sights and sounds of crime scene can be recorded.
• Provides comparison to determine if scene has been
altered or evidence moved during investigation.
– Introduce with case #, date, location
– Begin with surroundings (include entrance/exits)
– Tape Evidence (wide angle, close-up)
– Victims viewpoint
– Do not narrate the video or discuss contents and edit
original video
Videotape
• The filming should begin outside an indoor crime
scene or with an overall pan of the outdoor
location.
• The detective should narrate the videotape by
recording the audio portion as the videotape is
shot.
• The narration should include the name of the
speaker, time, date, location, case number, and
other pertinent identifying information.
• If videotapes are to be used as evidence, they
should not be edited or erased.
• Courts may or may not admit these tapes.
3. Photographing the Crime Scene
• “one picture is worth a thousand words”
• The crime scene must not be altered
– 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
– Take examination quality photographs (used by
experts to interpret evidence)
– Every photo should be recorded in a log
Crime Scene Photography
• All areas where the crime took place, entries and exits
should be photographed at different angles
• It is important to have close-up shots and far-away shots
• Evidence should be photographed with a ruler as a point
of reference
• The 35-mm single-lens reflex camera offers the greatest
versatility.
• Polaroid cameras are useful for identification
photographs.
• Digital cameras represent the latest technology and
deserve consideration. Instead of film, photographic
images are stored on magnetic devices.
Number & importance of Photographs
• It is better to overshoot a crime scene (take more
photographs than are necessary)
• They aid in refreshing the memories of witnesses and
investigators and show the relationships of items of
evidence at the crime scene.
• A very important purpose of crime scene photographs is
that they help to convey an image of the crime scene
and the circumstances of the crime to the court.
Types of Photographs
• Location: Photographs of the location of the crime
scene should be made.
• Witness photographs. Witness photographs are overall
photos of the CS. Long- and intermediate-range
photographs should be taken to show perspective and
the relative positions of different items found at the crime
scene.
• Close-up photographs. Close-up pictures should also
be taken to further clarify the scene.
• Two photographs should be routinely taken:
• (1) one showing the item as it actually appears and
• (2) a photograph of the same item with a ruler included
• Evidence photographs
Admissibility of Photographs
• For a photograph to be admissible in court, the
investigator must be able to testify that it accurately
depicts the area shown.
• To be accurate, it must represent the subject matter
properly in terms of color, scale, and form.
• Photographs must be in focus and should show the
relationships and distances between objects.
• All negatives from the crime scene photographs should
be retained. They are important to demonstrate that the
picture has not been altered also for enlargement.
Sketching the Crime Scene
• A sketch is an illustrative diagram or drawing that accurately
depicts the appearance of the crime scene.
• After photographs are taken, the investigator will sketch the
crime scene.
• Goal is to record exact position of all evidence to aid in
reconstruction.
• Sketches clarify the appearance of the crime scene and make it
easier to comprehend.
• It also give the relative distance between two objects at the CS.
• It is drawn by a draftsman or forensic surveyor.
• Sketches help investigators recall details of the crime scene.
• They also aid prosecutors, courts, and juries to better
understand the crime scene.
Importance of Sketches
• Sketches offer a permanent record of the relationship of
items at the scene to each other and help to supplement
photographs.
• They depict the overall layout of the location more easily
than can be accomplished by photographs.
• Sketches also allow for selectivity.
• A sketch may be drawn purposely to leave out
extraneous or confusing details that would be recorded
in a photograph.
• Distances can be shown over large areas and
topography can be easily illustrated.
4. Sketching the Crime Scene
• 2 types of sketches exist
– 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.
• Three techniques of measurement are used:
X Y X Y X Y
30°
e e e
Triangulation Baseline Polar Coordinates
Types of Sketches
1. Coordinate method : This method uses the principles of
measuring the distance of an object, such as a body,
from two fixed points.
• One form of the coordinate method involves the use of a
baseline, which is drawn between two known points.
• The baseline may also be a wall or drawn as a
mathematical centre of a room, the exact dimension of
which is known.
• The measurements of a given item are then taken from
left to right along the baseline to a point at right angles to
the item which is to be plotted.
2. Triangulation method: The triangulation method
requires three measurements:
• base;
• shortest side of the triangle; and
• longest side of the triangle.
• Crime scene sketches require
– 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
5. Searching the Crime Scene
• After scene documentation, a more thorough search of the scene
is completed.
• Systematic search ensures no piece of physical evidence is missed.
• 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
• As a simple, general rule, the most fragile evidence should be
collected first.
• A systematic search of the crime scene should be conducted.
• Thoroughness is the goal of the search plan
• Indoor crime scene searches are best done with two persons.
Crime scene search patterns
• Crime scene is usually searched in
segments (a) Spiral
– 4 types of segments exist
• Spiral search method- Search
starts at an outer point and (b) Strip/Line
gradually moves toward the center
• Grid method- Crime scene divided
into a grid and each grid segment
is searched (c) Grid
• Strip or line search- Crime scene
divided into strips and each strip is
searched
(d) Zone/Quadrant
• Quadrant or zone search- Crime
scene divided into quadrants and
each quadrant is searched.
• Wheel or ray method: Best on
(e) Wheel/pie/ray
small circular crime scenes
Wheel or ray method—best on small,
circular crime scenes
Searching Patterns
• Evidence must also be searched and collected from the
body (if victim died) by the medical examiner
• Evidence needed includes
• Victim’s clothing
• Fingernail scrapings
• Head and pubic hairs
• Blood
• Vaginal, anal, and oral swabs (sex crimes)
• Recovered bullets from the body
• Hand swabs from shooting victims
Reconstruction of Crime Scene
There are three types of reconstruction:
1. Specific incident reconstruction: this relates to
reconstruction of traffic accident, homicide, bombing etc
2. Specific event reconstruction like sequence, direction,
relation etc
3. Specific physical evidence reconstruction like blood
pattern, glass fractures, firearm, etc.
Steps in Reconstruction
1. Recognition of evidences
2. Documentation
3. Collection of evidence
4. Hypothetical formulation
5. Scientific testing
6. Criminal profiling
7. Conclusion
