Bagging Of Evidence

When evidence has been identified and collected at a crime scene it must be placed into an evidence bag and sealed to prevent contamination occurring when the evidence is transported to the forensic laboratory to be analysed. There are different types of evidence bags available to place evidence into depending on the size of the evidence and the type of evidence it is. The range of evidence bags available to scenes of crime officers include; plastic bags which can have test tubes containing swabs of biological evidence placed into them. Paper evidence bags can have evidence with biological evidence on it placed into them, such as items of clothing that are covered in blood. Or pieces of evidence that have suspected fingerprints on them, paper bags are superior to plastic bags when having exposed biological evidence placed into them as they allow the fluids to dry if still wet and also prevent them from deteriorating due to the condensation which would be caused in a plastic bag. Boxes can be used at a crime scene to place weapons such as knives or hammers into, these boxes allow the evidence to be secured to prevent it from moving around and also as the boxes are reinforced unlike the bags it can prevent the weapons piercing through and potentially harming someone. Containers can also be used at a crime scene to place evidence such as drugs in, the containers can be sealed to prevent contamination occurring and also prevent the evidence being tampered with.

In relation to the procedure of bagging evidence in the case of the murders of Nicola Brown and Ronald Goldman, a number of detrimental errors can be identified. Firstly separate pieces of blood evidence, belonging to Nicole, Ronald and what was found to be OJ Simpson, were placed within the same evidence bags. This therefore led to all of the blood evidence becoming cross contaminated, this led to the evidence being criticised and thrown out in the eventual court case that occurred.

Another example of where mistakes were made in the bagging of the evidence at the crime scene was that blood soaked items were packaged in plastic evidence bags whilst still wet. This therefore caused critical changes of the evidence to occur due to the degradation of DNA by bacteria. This mistake therefore did not allow any results to be obtained from the DNA analysis. The evidence on the clothing could have been important in identifying the perpetrator; therefore this mistake was detrimental to the case.