1. CRIME INVESTIGATION PLANS
Two types of plans 1. Sketch plan 2. Photo plan

2. PLAN
Sketch plan
is a preliminary plan that is less detailed than a working drawing.
Characteristics of sketch plan
The I/O draws a rough sketch on the scene, which is redrawn properly after I/O returns to office –
If it is drawn in proportion but according to a fixed scale, it is called a sketch plan
If it is drawn according to a fixed scale, it is simply called a plan
NB – Usually only draftsman may draw plans according to scale

3. Sketch plan
PURPOSE
To place before court a reproduction of the scene in a small and manageable size
It is an important source of information regarding the actual scene – it is an indication of what the I/O found.
It may be used to prove or disprove a fact in court.

4. Sketch plan TERMS According to scale:
That the measurements indicated on plan correspond with the measurements taken at the scene.
With the difference that a smaller measurement unit is used when the plan is drawn.
In proportion
When the measurements at the scene are paced off and drawn in accordance with a known method.
NB – the plan drawn will be correct in proportion, but because the measurement were paced and not taken with a tape measure, it will be a sketch plan

5. Sketch plan – method of measurement
Triangulation
Consists of three sides of which the angles total 180 degrees ( ) or ( )
The distance between two points on a base line must be known and also established
There must be two known or established points to a third point
Rectangular
All measurements are taken rectangular (90 degrees) from base line.
Base line
any existing straight line at or near the scene.
The straight edges of a straight road, fences etc
Can be created by making use of a piece of string or the tape-measure

6. Sketch plan - points Fixed point
Any object which is not easily removed
Purpose- in case of inspection in loco where reconstruction is required, it makes it easier to reconstruct
It must be linked to scene by exact measurements
It must be indicated on final plan
North point
It must appear on all plans
It must not be too big or too small
True North (TN) should never appear on the plan
Where the North point is not known – it must be determined

7. Sketch plan – rough/ draft
Use at least A4 size paper,
Must contain all measurements taken,
Contain the construction lines of method used,
Full description of all points’
Contain a note – reflecting who indicated the points,
It must be filed in docket (clip A)
Can only be produced as exhibit in court if the draftsman himself, refers to it during giving evidence –
If not referred by I/O then it is treated as privilege (section 234 of CPA)

8. POINT OF IMPACT
Refers to a point at which two object came in contact with each other
Can be established through –
Observation ie tyre marks of the road surface
It can differ from witness to witness
Every alleged point of impact must be indicated on the plan

9. PROCEDURE Step 1 Make overall analysis of the scene
Plan – decide what to include?
Sequence – clockwise or antic- clockwise
Step 2
Take measurements’
Measure scene from outside to inside
Movable points should not be measured as fixed points
Step 3
Measure object (evidence) with reference to fixed points
Obtain accurate measurements,
Step 4
Take notes of all items
Step 5
Compile a legend (key)
Step 6
Reassess the sketch before leaving scene

10. Example of sketch plan