At crime scenes the risk of contamination ought to be be minimised as far as is practically possible. That might mean staying away if you have a cold.
Anyone suffering from a short-term medical condition that causes the shedding of body fluids or particles (for example, colds, coughs, influenza, elevated temperature promoting sweating or hayfever) should be actively discouraged from attending the scene.
So says a new 45-page official document by the Forensic Science Regulator, ‘Control and avoidance of contamination in crime scene examination involving DNA evidence recovery’ that you can view on the gov.uk website.
A key element, especially for serious and major crimes where a crime scene manager (CSM) or equivalent is deployed, is to manage activities both within and outside the scene and at other relevant locations in a strategic and coherent fashion to ensure that contamination risks are understood and mitigated as far as practically possible.
Cordons
On cordons for example, the guidance asks that cordons shall be ‘sufficient and positioned appropriately as soon as it is safe to do so and should include all known or possible routes’, to protect the scene against contamination; and a log should be kept of who attends inside the cordon. Access to the scene should be controlled as a single point of entry; cars should be parked in a designated area, outside the cordon ‘but as near to the head of the common approach path as possible’. Again, this is to minimise potential contamination.
The document also goes into contamination risks and use of personal protection equipment (PPE) such as face masks; use of sniffer dogs to search for evidence; the hand-over of a scene to new staff; and record keeping.
Visit https://www.gov.uk/government/publications/crime-scene-dna-anti-contamination-guidance.
