Introduction
A scene of crime is a spot, area or surrounding where an act which resulted into a crime took place. A crime scene is visited with a view to investigating a criminal act. The key principle of crime scene management is Locard’s Exchange Principle which states that every contact leaves a trace. There are three types of crime scenes namely indoor, outdoor and conveyance crime scenes.
- Indoor scene
- Easy to demarcate
- Easy to secure
- Less exposure to contamination
- Outdoor scene
- Difficult to demarcate
- Difficult to secure
- Vulnerable to contamination
- Vulnerable to changes in weather conditions
- Conveyance scene
- Easy to demarcate
- Easy to secure
- Difficult to search
- Less exposure to contamination
The reasons for investigating a crime scene are to identify the guilty party, to locate the guilty party and to provide evidence of his guilty.
Crime Scene Teams
1. Team Leader
The role of the Team Leader is the overall supervision of the activities at the scene. He conducts the initial walk through at the scene, determines demarcations of the scene, determines search patterns and assigns roles to other team members. Importantly, he controls access to the scene to avoid contamination and coordinates with other law enforcement agencies needed at the scene. It is the responsibility of the team leader to take charge of all the evidence at the scene at to briefs the superiors and the press and prepare the crime scene report.
2. Security team
The Security Team ensures safety of personnel at the scene. They evacuate casualties from the scene, control entry and exit into the crime scene area, keep unauthorized persons at bay and guard the equipment and any evidence that have been removed from the scene.
3. Evidence Recovery Team
The Search/Evidence Recovery Team searches the scene area for evidence, flags all potential evidence, collects evidence after they have been photographed, marked and recorded and packages evidence.
4. Photographer and Evidence Recorder
The first role of the Photographer is to take pictures of the entire undisturbed scene. This is followed by photographing the entire crime scene process including taking photographs of the packaged evidence, latent fingerprints and other impression evidence. After the scene processing is complete, he takes photographs of the completed scene.
The Evidence Recorder numbers the flagged evidence, labels the evidence containers, prepares the inventory and fills out chain of custody forms.
6. Sketcher
The Sketchers prepare a rough sketch of the scene showing demarcations, maps all evidence in relation to each other, takes measurements of evidence relative to each other and to a key evidence point, put measurements on the sketch and prepares a fine sketch of the crime scene and evidence.