Explain how evidence is processed
Types of Evidence
There are two types of evidence. Physical Evidence and Testimonial Evidence. Physical
evidence refers to real-world items like hairs, fibres, fingerprints, and biological material. Testimonial
evidence is statements from the defendant, a victim or witness.
Physical Evidence
Physical evidence is an essential part of prosecutions and court cases, and it is used in virtually all
criminal cases. This might be as a result of Locards Exchange Principle, which states that every time a
person enters a space, something is added to and something is taken away. To put it another way,
every interaction leaves a trace. This applies to contact between individuals as well as between and
individual and the physical environment. Scene of crime officers always work on the principle that
physical evidence is left behind at every crime scene as a result of Locards exchange principle. This
exchange, however, can become problematic in legal contexts, as was the case with Barry George,
who was wrongfully imprisoned for murder when a tenth of a centimetre of gunshot residue was
discovered in his jacket pocket. According to reports, this gunshot residue came from police firearms
that were brought inside his apartment during a search and, because to Locards exchange principle,
ended up in his pocket, which resulted in a miscarriage of justice.
But dealing with an outside crime scene might make handling physical evidence challenging. For
instance, the environment may contaminate and destroy evidence, making it unusable for an
investigation. In addition, adverse weather conditions like rain or wind could cause the evidence to
be lost or destroyed. When testing the evidence, it is important to take into account the fact that
outdoor crime scenes frequently draw the attention of the media, which may taint the evidence and
affect its credibility. It is essential for the police to secure the crime scene by putting up temporary
buildings and ensure that the scene is not polluted by donning bodysuits and utilising stepping stools
when gathering evidence in order to prevent these potential problems.
Once evidence has been found, it must be handled in different ways.
Blood stains can be collected on sterile material, if still in a liquid form, and left to dry at room
temperature. They should be brought to the lab for the forensic specialists to analyse within 28
hours. The forensic analysts create a DNA profile of the blood. If the blood on the item has already
dried, it should be put in a container, sealed, and labelled. The blood stains evidence is transported
in a secure police van.