crimescene sketching methods

Crime Scene Sketching methods-

Baseline line Mapping

Rectangular Coordinate Mapping

Triangulation mapping

Polar/Grid Coordination Mapping

Advance Mapping Technique

Sketching-

A crime scene sketch is a permanent record of the size and distance relationship of the crime scene and the physical evidence within it.

The sketch serves to clarify the special information present within the photographs and video documentation, because the other methods do not allow the viewer to easily gauge distances and dimensions.

A sketch is the most simplistic manner in which to present crime scene layout and measurements.

Why is a sketch important to crime scene documentation?

It accurately portrays the physical facts.

It relates to the sequence of events at the scene.

 It establishes the precise location and relationship of objects and evidence at the scene.

It helps to create a mental picture of the scene for those not present.

It is a permanent record of the scene.

It usually is admissible in court.

It assists in interviewing and interrogating.

It assists in preparing the written investigative report.

It assists in presenting the case in court. Well-prepared sketches and drawings help judges, juries, witnesses, and others to visualize the crime scene.

Types of Sketches-

Rough Sketch

FORENSIC SCIENCE

Rough Sketches are developed typically during the crime scene assessment/preliminary scene evaluation phase to assist with development of a strategic plan for processing.

The sketch is not done to scale.

Search methods - Finished Sketch

Crime Scene Mapping -

FORENSIC SCIENCE

Mapping is the term associated with crime scene measurements. Sometimes a person may sketch but not map, meaning that he or she draws a sketch of an area but does not apply measurements to the sketch produced and items represented.

-> Rarely, however, will one map without sketching (i.e., record measurements with no graphical representation for what the measurements represent).

Sometimes this step is referred to as measuring. There are a variety of methods for mapping a crime scene, depending upon whether the crime scene is an interior or exterior scene.

As this is an introductory text, only the most basic and most often used methods are covered here.

Types of Sketches-

FORENSIC SCIENCE

The basic types of mapping methods utilized for crime scene sketching and mapping are:

(a) baseline,

(b) rectangular coordinates,

(c) triangulation, and

(d) polar/grid coordinates

Baseline Mapping-

1. Co-ordinate or Baseline Method -

This method involves the principles of principles of measuring the distance of an object; such as a dead body, from two fixed points.

2. Triangulation Method -

• This method is used for the sketching of outdoor crime scene such as a park, beach, or paddock. It requires three measurements:

O The base such as side of a house.

Shortest side of the triangle.

o Longest side of the triangle.

Cross Projection Mapping-

3. Cross Projection method:

When physical evidence is found on roof, walls, windows, etc. then distances and height both are required to be measured. This method is known as cross-projection method. All four walls, roofs, doors, and windows are shown in the sketch

4. Polar method:

This method is suitable for sketching of an outdoor crime scene with large area. In this method a focal point is selected first which could be a tree, pond, electric pole, etc.