Crime Scene Investigation

Crime Scene Investigation (CSI) is the systematic process of documenting, collecting and preserving physical evidence from the location where a crime has occurred. The crime scene is the primary source of physical evidence and its proper handling is fundamental to a successful investigation.

The investigation follows a methodical sequence – securing and protecting the scene, conducting a preliminary survey, photographing and sketching, systematic search, and the collection, labelling and packaging of evidence – all while maintaining an unbroken chain of custody.

Securing the Scene

The first responder's primary duty is to protect the scene from contamination, preserve life and prevent the loss, alteration or addition of evidence. A cordon is established and access is restricted to authorised personnel only.

Methods of Search

Depending on the size and nature of the scene, investigators use search patterns such as the spiral, strip or line, grid, zone and wheel methods to ensure that no area is overlooked and all evidence is recovered systematically.