On the scene - Collecting the evidence

Crime scene investigation Crime scene investigation Crime scene investigation

Evidence from a crime scene is carefully collected and stored to ensure that it is preserved and uncontaminated.

Each item is packaged separately and sealed to safeguard it from cross-contamination.

Fragile evidence is collected first to prevent it from being damaged or destroyed

Fingerprints are photographed and dusted with powder to reveal their unique spiral pattern. A copy of this can be taken using a special lifting tape before they are sent to the fingerprint bureau for examination.

All details of a crime scene must be carefully recorded before anything is disturbed.

CSI’s use a variety of equipment when carrying out crime scene examinations.

Digital 35mm Single Lens Reflex  - DSLR - cameras are used to photographically record evidence and photographs are processed at the Force Central Colour Processing Unit (CCPU).

Investigators also have the capability to record a 360 degree image of the crime scene if required using the iPIX system.

Fingerprint examinations are carried out using a variety of brushes depending on the type of surface to be examined which also determines the type of powder. The three common powder types are granular, flake and magnetic powders. Evidence is recovered using specialist recovery materials produced to an extremely high standard to ensure the samples they contain are contaminant free.

Forensic evidence is usually either physical such as fingerprints or Footwear impressions or biological such as blood or hair samples. Police will often put up tents at scenes of crime to prevent evidence being destroyed by the weather.

Ultraviolet and infrared lights are often used to pick out trace evidence that cannot be seen by the naked eye.