Investigative Photography and Crime Scene Sketches

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Investigative PhotographyandCrime Scene
Sketches
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Crime Scene Photography

• One of the FIRST investigative tasks!!!

• Types of cameras used

35mm SLR
Video
Digital
Polaroid
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Crime Scene Photography

• Advantages of photographs

Can be taken immediately
Can accurately depict crime scene
Creates interest
Supports testimony

• Disadvantages of photographs

Do not show actual distances
Can be distorted
Digital images can be altered
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Advantages of Video Taping

• Increases Intoxication convictions - DUI

• Enhances officer integrity

• Provides officer safety

• Documents traffic violations

• Reduces court time for officers

• Lowers liability for misconduct claims

• Documents probable cause and evidence

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Disadvantages of Video Taping

• Records unwanted sound

• Documents errors made by officers and technicians

• Officers not always trained

• Discrepancies with Time/Date stamp

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Types of Photographs
Establishing photographs depict an overall view
of the scene, buildings, approach and escape
routes, witnesses, etc.
Medium-range photographs depict the relationship
between objects, concentrates more on the
immediate scene.
Close-up photographs depict individual items of
evidence.
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This establishing photograph depicts the overall
crime scene.
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This medium-range photograph depicts the actual
scene and relationship of evidence.
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This close-up photograph depicts a single item of
evidence.
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Flash photography is often needed during the day.
As seen in the photograph, the cameras eye is
fooled by the bright brickwork, while the
evidence is in darkness.
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Same photograph, but with a flash. Now the
evidence can be seen.
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Photographs should contain rulers or objects to
help establish the size of the evidence. In this
instance, the known length of the bill can be
used as a scale to determine the length of the
knife.
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Macroscopic photographs depict details of
objects, and are taken at extreme close range.
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An essential documentation step in crime scene
processing protocol
Sketch
Keys to Crime Scene sketch

• Dimension
• Distance
• Content
• Relationship among items of evidence

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Purposes of the sketch

• Record the exact location and relationship of
  evidence to surroundings.

• Refresh the memory of the investigator

• Provide permanent record of conditions

• Assist prosecutor, judge and jury to understand
  conditions at the crime scene

• Help in questioning suspects and witnesses

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The General Uses of Photography

• Crime scene documentation

• Surveillance of people and locations

• Mug shots

• Line-ups

• Laboratory examination of evidence

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Crime Scene Sketches
Sketches are important supplements to photographs
and crime scene reports. Sketches.

• Accurately portray physical facts

• Relate to the sequence of events

• Establish locations and relationships

• Provide an overall picture of the scene

• Are a permanent record of the scene

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Crime Scene Sketches
The rough sketch is drawn at the crime scene. It
is not a finish product, although it does contain
measurements and other data.
The finished sketch is often drawn by a draftsman
to show proper relationships and scales. The
finished sketch is more presentable for court
presentations.
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Sketch Requirements

• Rough sketch need not be to scale but should be
  proportional showing accurate measurements to the
  nearest ¼ inch of the exact placement of the
  evidence and victim
• No changes should be made to rough sketch once
  you leave the scene
• Legend or key should be on both rough and
  finished drawings

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• Objects in scene should be marked with letters
• Evidence marked by a circled number
• North indicated on both drawings
• Must show all relevant materials
• Rough sketch may be made in pencil but final
  sketch must be made in ink

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Steps in Sketching the Crime Scene
1. Observe the scene and plan the sketch
2. Measure distances
3. Outline the area (area dimensions)
4. Locate and draw objects and evidence within
the sketch
5. Record all details
6. Depict legend, title, scale and direction of
North
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• On the final sketch
• Omit measurement lines
• Must include all items that were in the rough
  sketch no additions, no deletions
• Scale notation must be noted
• Best if made by same investigator that made the
  rough sketch
• All measurements should face the same direction.

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Final sketch continued

• Arrow heads should touch measurement lines
• All hidden objects should be indicated by dotted
  lines
• No conclusions should be noted on the drawings
• Objects located by triangulation or coordinate
  method when possible

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A Rough sketch is done by the technician
recording the exact placement of evidence and
victim.
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Accurate measurements to two fixed points must be
recorded so that a scaled final sketch can be
prepared for court presentation.
What are good examples of fixed points?
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Triangulation Method of Locating Evidence
A
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Item A is 10 from the SE corner of the room, and
8 from the SW corner of the room. These
measurements will ALWAYS intersect at item As
location.
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Triangulation Method of Locating Evidence
A
desk
Evidence must be triangulated to two fixed
points. Not using the corners of the room, how
would object A be triangulated?
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Triangulation Method of Locating Evidence
A
desk
First, the desk is not fixed, as it is not
touching the wall and its location has not been
determined. To fix the desk, do this
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Triangulation Method of Locating Evidence
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A
desk
1
Now that the desk has been fixed, object A can be
fixed from two fixed points from the desk, as
such
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Triangulation Method of Locating Evidence
3
A
5
desk
6
1
Now that the desk has been fixed, object A can be
fixed from two fixed points from the desk, as
such
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Triangulation Method of Locating Evidence
A
desk
In this scenario, the desk is flush against the
wall. How would object A be triangulated?
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Triangulation Method of Locating Evidence
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A
5
desk
6
The flush side of the desk is already fixed. One
measurement is required to place the desk along
the wall. Object A is then triangulated as usual.
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Triangulation Method of Locating Evidence
desk
A
This desk is flush in the corner against both
walls. How would object A be triangulated?
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Triangulation Method of Locating Evidence
desk
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A
5
Since two sides of the desk are already fixed,
object A is triangulated as usual.
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Triangulation Method of Locating Evidence
desk
6
A
5
2
2
B
Once evidence is triangulated, it can become a
fixed point to triangulate other items of
evidence. In this case, object B.
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Rectangular-Coordinate Method
A
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B
6
10
6
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Azimuth Method of Triangulation
Tree
340
160
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Shed
220
N
Reverse azimuth340-180160
Reverse azimuth40180220
E
W
Body
S
Compass
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Administrative Data
LEGENDA. VictimB. RevolverC. Shell CasingD.
Blood Stain
TITLECase 1234-2001Location Payson Hall, Room
111Victim State of New YorkOccurred Oct 31,
2001, 2300Drawn by Detective GilbertVerified
by Detective Marlowe
Not to Scale
North
Or¼ 1 foot
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Rules for Drawing Sketches

• Never measure through space

• Rotating items require measurements at
  opposite ends

• Oddly shaped items, such as puddles of liquids,
  are triangulated from center of mass

• Do not cross measurement lines

• Always have the sketch verified

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10
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Since the blood droplets are of no particular
defined shape, they are triangulated to the
center of mass
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Projection Sketch
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What's missing?
Rough sketch of out door crime scene
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Where are the fixed points in this room?
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Final Sketch
Rough Sketch
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The Finished Sketch

• Is usually prepared for courtroom presentation.

• Must be to scale i.e. ¼ in. 1 ft.

• Units used must be consistent
• i.e. make all measurements in metric or in
  feet/inches do not combine.

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Bird's eye view 2 dimentional representation
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Bird's eye view 3 dimentional representation
                                                                                                                                                                                                                                                                                                                                                     
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Computer representation
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