An outline of the different types of evidence recovered from the investigation

There are three different categories of evidence which can be potentially collected from any one crime scene; these are; biological, chemical and physical.

Biological evidence refers to evidence which comes from a human being, which may include a form of bodily fluids. Types of biological evidence include; blood, saliva, semen, hair fibres, skin cells, tissue and teeth. In addition, biological evidence which is collected can be a source of DNA, thus having the potential of linking an individual to a crime scene. Some samples of biological evidence that is collected from the crime scene can be more probative than others, this meaning they having the ability of demonstrating that the sample identify who it belongs to.  

Chemical evidence refers to evidence that is made up of elements and compounds that are found on various objects, individuals or within solutions. Types of chemical evidence an analysis will examine may include; drugs, paints, remnants of explosives, gunshot residue, accelerants, medicine and fire debris. The evidence can be tested to identify various things, for example if suspected gunshot residue was found on an individual’s clothing, it could be tested to see if it tests positive for gunshot residue, and if so they can potentially link the individual to the crime that is under examination.

Physical evidence within a criminal investigation typically refers to objects that are concealed within the crime scene, or additionally it could come in the form of witness statements or surveillance. Physical evidence that is obtained can include objects such as potential murder weapons, abandoned vehicles, footprints, CCTV and witness statements. Analysis of physical evidence may include taking photography, along with measurements of the item. Once the item has been photographed the analyst will potentially check for any biological evidence contained upon the object, such as fingerprints, blood stains or saliva.