(For CJ327 Assignment/Project Considerations)
Forensic Photography for the Crime Scene Technician
Forensic Photography for the
Crime Scene Technician
NOTE: This is the student outline for the Crime Scene Photography course in the Crime Scene Investigation Certificate Program at the University of California at Riverside. Instructor: Steven Staggs.
I. TECHNICAL PHOTOGRAPHY
A. Basic equipment for crime scene photography
1. Camera(s)
2. Normal lens
3. Wide angle lens
4. Close-up lenses or accessories
5. Filters
6. Electronic flash(s)
7. Remote or sync cord for electronic flash(s)
8. Extra camera and flash batteries
9. Locking cable release
10. Tripod
11. Film
12. Owner's manuals for camera and flash
13. Notebook and pen
14. Ruler
15. Gray card
16. Index cards and felt pen
17. Flashlight
B. Lenses
1. Normal lens
2. Wide angle lens
3. Other lenses
C. Care and maintenance of crime scene photography equipment
1. Cleaning lens and camera
2. Camera repair
3. Protection from extreme heat and cold
4. Protection from rain
D.Film
1. Color vs. black and white
2. Print film vs. slide film
3. Film speed
4. Matching film to the light source
II. CRIME SCENE PHOTOGRAPHY IS TECHNICAL PHOTOGRAPHY.
A. Photographs must be correctly exposed, have maximum depth
of field, be free from distortion and be in sharp focus
1. Correctly exposed
a. Exposure is controlled by the shutter speed and
lens aperture
b. Automated camera exposure systems and automatic
flash units can be fooled and give incorrect
exposures
c. Front, side and back lighting
d. Light meters
e. Flair
f. Using gray card
g. Bracketing exposures
2. Maximum depth of field
a. Depth of field is the area in a photograph in
which objects are in sharp focus
b. How to control depth of field
c. Zone focusing
(1) Preview depth of field
3. Free from distortion (must have good perspective)
a. Use a normal focal length lens when ever
possible
b. Keep the camera as level as possible
c. Photograph with the camera at eye level when
ever possible
4. Sharp focus
a. Keep the camera steady
b. Focus carefully and use maximum depth of field
c. Look at the frame of your scene
III. FLASH AND NIGHT PHOTOGRAPHY
A. Types of flash illumination
1. Manual flash
a. Set f/stop for the flash-to-subject distance
2. Automatic flash
a. Uses distance ranges
b. A change to a new range requires a change in
f/stop
c. Never work an automatic flash at its maximum
range, especially in less than ideal conditions
d. When in automatic flash, make sure the shutter
speed dial is set to the flash synchronization
speed
e. When photographing a high key scene (light or
reflective background) bracket <197> opening up
one or two f/stops
3. Dedicated flash
a. Sets correct flash synchronization speed when
the flash is in operation. Still uses
automatic sensor and ranges. The photographer
must set the appropriate f/stop for the
distance range
OR
b. Sets the correct flash synchronization speed
and f/stop for the automatic range selected
4. Dedicated TTL (Through-the-lens)
a. Uses a sensor inside the camera
b. Use smaller f/stops for short distances and
larger f/stops for long distances
c. For compensation or bracketing use the exposure
compensation dial
B. Problems with electronic flash
1. Flash synchronization
2. Coverage
a. Distances -- inverse square law of light
b. Long distances when outdoors at night or at
arson scenes
3. Reflective surfaces
a. Automatic flash units can shut off too soon due
to reflected light
4. Rain
C. Lighting techniques
1. Electronic flash (NOTE:Disregard the light meter in
the camera when using electronic flash)
a. Flash mounted on camera
b. Flash off camera
c. Bounce flash
(1) Bounce off a white or light colored
surface
(2) Manual flash: add the distance up and down
for the flash-to-subject distance then
figure in the absorbance loss (one to
three f/stops)
(3) Automatic flash with sensor facing the
subject: use a range for two times or more
times the actual flash-to-subject distance
d. Multiple flash
(1) Distance the flash units to provide the
same f/stop for each flash
2. Available light (no electronic flash)
3. Painting with light
a. The shutter is left open while the light source
is moved around until all of the scene is
properly illuminated
b. Procedure
(1) Mount the camera on a sturdy tripod
(2) Equip the camera with a lens shade (if
available)
(3) Screw a locking cable release into the
camera shutter release
(4) Set the shutter speed dial to B (bulb)
(5) Determine the f/stop based on the flash to
subject distance (not the camera to
subject distance)
(6) Focus carefully
(7) Depress the cable release and lock it to
hold the shutter open
(8) Fire the electronic flash to light areas
of the scene. The number of flashes and
angle of the flashes will depend on the
size and character of the scene. Do not
point the flash directly at the camera and
keep yourself out of the view of the
camera
(9) Unlock the cable release and allow the
shutter to close
(10) Advance the film
IV. CRIME SCENE PHOTOGRAPHY
A. Purpose of Crime Scene Photography
1. To record the original scene and related areas
2. To record the initial appearance of physical
evidence
3. It will provide investigators and others with this
permanent visual record of the scene for later use
4. Photographs are also used in court trials and
hearings
B. Admissibility of photographic evidence
1. Three major points of qualification of a photograph
in court
a. Object pictured must be material or relevant to
the point in issue
b. The photograph must not appeal to the emotions
or tend to prejudice the court or jury
c. The photograph must be free from distortion and
not misrepresent the scene or the object it
purports to reproduce
2. You do not need to be an expert in photography to
take crime scene photographs or testify about them
V. GENERAL CRIME SCENE PHOTOGRAPHY
A. Photographs are one way to record a crime scene
1. Field notes
2. Photographs
3. Sketches
B. Photographs
1. What photographs can show
2. What photographs do not show
C. Five steps in recording the crime scene
1. Secure the scene
2. Take preliminary notes
3. Take overview photographs
4. Make a basic sketch
5. Record each item of evidence
D. Taking overview photographs
1. Purpose
a. To show the scene exactly as it was when you
first saw it
(1) If something was moved before you arrived,
don't try to reconstruct the scene as it
was. The photographs should show the
scene as you found it
2. Major crime photography
a. First discuss the crime, evidence and
photographs needed with other investigators at
the scene
b. Be careful not to destroy any evidence while
taking the photographs
c. Outside the scene
(1) Exterior of the building where the crime
occurred and in some cases the whole
locale
(2) Aerial photographs of the scene and the
surrounding area can be useful in some
types of cases
(3) Original series of photographs should also
show all doors, windows and other means of
entrance or exit
d. Inside the scene
(1) Begin with a view of the entrance
(2) Then photograph the scene as it appears
when you first step into the room
(3) Next, move around the room to get
photographs of all the walls
(a) These photographs should also show
the positions of any potential items
of evidence
(4) Include photographs of other rooms
connected with the actual crime scene
3. Using video to record the crime scene
a. Frequently valuable to show an overview of the
scene
E. Photographs to record items of evidence
1. Take two photographs of each item of evidence
a. One should be an orientation (midrange) shot to
show how the item is related to its
surroundings
b. The second photograph should be a close-up to
bring out the details of the object itself
2. Measuring and marking devices
a. Take two photographs if a marking or measuring
device is used
(1) One photograph without the device, the
other with the device
(2) So the defence can't claim that the scene
was altered or that the device was
concealing anything important
VI. PHOTOGRAPHING SPECIFIC CRIME SCENES
Note:Each crime scene has unique characteristics and the type
of photographs needed will be determined at the scene by the
investigator familiar with the crime.
A. Homicide
1. Use color film
2. Photographs (example: homicide inside a residence)
a. Exterior of the building
b. Evidence outside the building
c. Entrance into the scene
d. Room in which the body was found
e. Adjoining rooms, hallways, stairwells
f. Body from five angles
g. Close-up of body wounds
h. Weapons
i. Trace evidence
j. Signs of activity prior to the homicide
k. Evidence of a struggle
l. View from positions witnesses had at time of
the crime
(1) Use a normal lens
m. Autopsy
B. Suicide, other dead body calls
1. If there is any doubt, photograph the scene as a
homicide
C. Burglaries
1. Photographs (residential or commercial burglaries)
a. Exterior of building
b. Point of entry
c. Entrance into scene
d. Interior views
e. Area from which valuable articles were removed
f. Damage to locks, safe, doors, toolmarks
g. Articles or tools left at the scene by the
suspect
h. Trace evidence
i. Other physical evidence
D. Assaults, injuries
1. Photographing injuries
a. Face of victim in the photographs
b. Bruises
c. Bite marks
(1) Orientation shot
(2) Close-up at 90 degree angle to avoid
distortion
(3) Ruler in same plane as bite mark
(4) Focus carefully
(5) Bracket exposures
2. Equipment
a. Always use color film and no filter
b. Use color charts and rulers
c. Flash unit with diffused lighting
E. Traffic Accidents and Hit and Run Cases
1. Photographs at the accident scene
a. Where the vehicles came to rest and in what
position
(1) Photographs should show the relationship
of each vehicle with each other
b. Damage to vehicles
(1) Technical photographs of damage to a
vehicle
(a) Do not take any oblique or corner
photographs to show damage for
reconstruction purposes because they
are not aligned with the axis of
the vehicle. They tend to conceal
the amount and direction of the
damage.
(b) Take six photographs. Two from each
side in line with the axles. Take
one of each end of the vehicle,
straight on. If possible take one
more from overhead
(c) Use electronic flash to fill in
shadows within the damage
c. Debris or marks on the roadway
d. View each driver had approaching the key point
of the accident.
e. View from the point a witness observed the
accident, at witness' eye level
f. Evidence to identify hit and run vehicles
2. Night photography
a. Use multiple flash, paint with light or
available light for extra long skidmarks or to
show two vehicles some distance apart
VII. USING FLASH FILL
A. Steps
1. Set the shutter speed to the camera's flash
synchronization speed (usually 1/60 second)
2. Use the camera's light meter to determine the
correct f/stop. Set that f/stop on your lens.
3. With the flash on manual, find the flash to subject
distance for the above f/stop.
4. Position the flash unit at that distance and take
the photograph.
VIII. PHOTOGRAPHING EVIDENCE
A. Fingerprints
1. When to photograph fingerprints
a. Before lifting on major cases or if the latent
may be destroyed when lifting
b. To bring out detail in a latent
2. Equipment
a. 1:1 cameras and copy cameras
b. 35mm cameras with macro or close-up lens
attachments
c. Gray card for available light exposures
3. Films
a. Well defined fingerprints can be photographed
with color film but black and white film
provides more contrast and is preferred for
latent print photography
(1) Kodak T-MAX film. Develop in T-MAX
developer while increasing the development
time by 25% for increased contrast.
(2) Kodak TECHNICAL PAN 2415 film has a
variable contrast range between high and
low and a variable speed of ISO 25 to 320.
(a) For high contrast expose at ISO 100
and develop in HC-110
(3) Kodak KODALITH film for highest contrast
(a) Packaged as Kodak Ektagraphic HC
Slide Film (HCS 135-36) and has an
approximate ISO of 8.
(b) If developed in D-76 or HC-110 there
will be a limited gray scale.
(4) Ilford XP-2 black and white film can be
processed in color processors
(a) ISO 400, fine grain with good
sharpness & resolution can be
processed in C-41 color chemistry
4. Filters
a. Color filters, when used in black and white
photography, can be used to build contrast by
either lightening or darkening the subject
(latent print) or by lightening or darkening
the background (background drop-out)
(1) To lighten a color, the color filter
closest to the color is used
(2) To darken a color, the opposite color
filter is used
(3) See Filter Chart for examples
5. Procedures
a. Establish the location of the latent
b. Close-up to show detail
(1) A 1:1 camera or device must be used, or
(2) A scale must be included in the photograph
on the same plane as the latent
(3) Photograph with the film plane parallel to
the latent surface
(4) Get as much depth of field as possible,
especially for curved surfaces
c. Exposure
(1) Available light exposures of latents with
normal contrast can be metered using a
gray card
(2) Bracketing may reveal more detail in
"low contrast" latents.
(a) Underexposing the film will separate
the steps on the white end of the
gray scale. Overexposure will
separate the steps on the black end
of the gray scale.
(b) The latitude for black and white film
is generally two stops underexposure
and six stops overexposure.
d. Specific types of fingerprint subjects
(1) Normal, dusted prints
(a) Usually can be photographed with no
problem
(2) Impressions in soft substances (wax,
putty, clay, adhesive tape, grease, etc.)
or in dust
(a) Use cross lighting at an oblique angle
(b) Preview with flashlight lighting
(3) Porous surfaces
(a) May need to use close to a 90 degree
lighting angle
(b) Preview with flashlight lighting
(4) Glass and mirrors
(a) Glass -- place white card or cloth
behind glass, use low oblique angle
of light
(5) Perspiration prints on glass
(a) Use back (transmitted) lighting and
diffusion screen
(6) Ninhydrin fingerprint
(a) Use normal black and white film
(T-MAX or PLUS-X) with a green filter
and increase development time 25%
B. Impressions
1. Footprints and tire tracks
a. Procedure
(1) Take an orientation photograph to show
where in the scene the impression is
located
(2) Take a close-up for detail
(a) Use a scale on the same plane as the
impression
(b) Keep the film plane parallel to the
plane of the impression
(c) Block out ambient light and use a
strong light source at different
angles to find the light angle(s)
that shows the best detail in the
impression -- then put the electronic
flash or light source at that angle
for the photograph
(3) Photograph tire impressions in sections
showing one circumference of the tire
(a) Use a tape measure for overlapping
photographs
C. Bloodstain photography
1. Use color film
2. Orientation photographs to show locations of
bloodstain evidence at the scene
3. Close-up photographs to show detail
a. Use a scale on the same plane as the bloodstain
b. Keep the film parallel to the plane of the
bloodstain
c. Use a low oblique light angle
D. Toolmarks
E. Serial numbers
F. Small items, copying, etc.
1. Close-up lenses and devices
2. Lighting