“Crime Scene Sketching” Types Of Sketches Perspectives: Purpose of Sketching: Methods:- Cross projection Methods • Triangulation method • Coordinate or Baseline Method • Polar Method

1. Presentation on topic,Presentation on topic,
“Crime Scene Sketching”
Presented By,
Palash A. Mehar
M.Sc. (Forensic Science) Part-I
Govt. Institute Of Forensic Science, Nagpur

2. SketchingSketching
Sketches are handy in depicting a scene of occurrence. In combination
with the photographs, the sketches provide an ideal representation of the scene.
 They indicate inter-distances between relevant objects.
Types Of Sketches
Rough Sketch Finished Sketch
 They indicate inter-distances between relevant objects.
 They indicate relevant evidence only.

3. Rough SketchRough Sketch
A draft representation
of all essential
information andinformation and
measurements at a
crime scene. This
sketch is drawn at the
crime scene.

4. Finished SketchFinished Sketch
 A precise rendering
of the crime scene,
usually drawn to
scale.scale.
 Finished sketch
must reflect
information
contained within the
rough sketch in
order to be
admissible evidence
in a courtroom.

6. Perspectives:Perspectives:--
There are two basic types of perspectives that are used for crime
scene sketches,
1) The overhead or ‘bird’s eye view’:-1) The overhead or ‘bird’s eye view’:-
A crime scene sketch is usually drawn from a looking-down or
overhead perspective. This type of perspective is most common type
and is most recognizable by other investigators and juries.
2) The elevation or ‘side-view’
Where appropriate or when the crime scene presents evidence at
various heights in a crime scene, a side view or elevation sketch can
be used.

7. Purpose of Sketching:Purpose of Sketching:--
These are helpful for the following,
 Refresh the memory of the investigating officer as well as witnesses.
 Illustrate the exact location and relationship between physical evidence and
surroundings.
 Provide the permanent record of : Provide the permanent record of :
Topography of the site
Vehicle’s path in road accident.
Position and distance of skid mark.
Movement of the culprit.
Distance involved in the large areas.
 Put the crime scene before prosecutor, judge and jusry in a understandable manner.
 Verify and correlate testimony of witnesses.
 Eliminate unnecessary and confusing details.

8. • Cross projection method
• Triangulation methodMethodsMethods • Triangulation method
• Coordinate or Baseline
Method
• Polar Method
MethodsMethods
ofof
SketchingSketching

9. Triangulation
Measurement
Method
Two fixed points are selected.
Measure the distance between them.
Measure the distance to objects in the scene
from each of these two points.
A & B are fixed points and X & Y are objects
in the scene.
Base Line
Coordinates
Measurement
Method
Two fixed points are selected, the objects are
measured along the line between the points and
at right angles to the line. Walls or tape
measures along the ground work well A & B
make the fixed line and X & Y are objects in the
scene.

10. Polar Coordinates
Measurement
Method
It is used for large outdoor scenes. Here instead
of drawing co-ordinates, the distances and
directions of the evidentiary objects are noted
with reference to a central (focal) point. The
Position are recorded on the sketches
accordingly.
Cross
projection
Method
When the physical evidence is found on roof, walls, windows, etc.
Then distances and height both are required to be measured.
All four walls, and the roof fold out and extended flat on the floor,
the walls, roof, doors and windows are shown in sketch.
All measurement with respect to the evidence found on walls,
windows, doors or roof are taken from each corner of the floor,
wall and roof fig. This is also called as extended coordinate
method.