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

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

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.

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

Sketch plan – method of measurement Triangulation Consists of three sides of which the angles total 180 degrees (90-30-60) or (90-45-45) 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

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

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)

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

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

Example of sketch plan