In the past decade, forensic science has been recognized as a powerful field due to its significance as supporting evidence in criminal cases. The development of techniques in handling and analysis of deoxyribonucleic acid (DNA) samples has influenced police investigators to rely on any information forensic science can offer. The combination of DNA analysis with the study of surrounding insects (entomology) and pollen (palynology) has resulted in an efficient and effective method in investigating criminal cases (Leclair et al., 2004).
The inclusion of forensic data in criminal investigations has thus transformed the process of conviction and to a certain extent, has overturned particular verdicts upon review of old cases. Unfortunately, the convicted individual of those old cases are usually sentenced to death and the DNA evidence is too late to overturn the sentence because the convict is already dead.
The act of crime scene investigation is designed to observe individuals, areas or objects that are of particular interest to an investigator in order to collect information and evidence that may be associated with a suspect and his related criminal activities (Walker, 2001). Physical surveillance is a method of examination of a particular area that is linked to a crime scene or a suspect. This may include inspecting the area when the crime took place, as well as the victim’s and suspect’s homes, vehicles and paraphernalia.
Examination will cover both the conditions of the places and items, as well as the position of the places and items in the particular areas. Physical surveillance is important in a crime scene investigation because it provides a way for the investigator to reconstruct the scene and make inferences on what actually happened during the incident (Gardner, 2005). Any area that is associated with a crime is identified as soon as a crime has been established or reported. In addition, these particular areas are protected from any type of disruption by putting a crime scene tape along the perimeter of the area concerned.
It has been reported that the most complicate part of an investigation is the establishment and protection of the boundaries of a crime scene because the signs related to a scene are often elusive to an investigator. Other investigators employ search dogs to facilitate the establishment and tracking of a crime scene. Photography is commonly employed in the physical surveillance of a crime scene. This visual documentation of an area is very helpful to an investigator because it physically records the features of the area before any other activity is performed to the crime scene.
Physical surveillance also involves marking all potential evidences to the crime. In addition to photographs, sketches of the crime scene are also important in physical surveillance of a specific area. Sketches are generally considered as essential information of crime scenes because these serve as detailed notes of the investigation, although the diagrammatic representation is of less quality than a simple photograph. Sketches provide measurements of the crime scene, including distances between two points of interest that are located within the area under investigation.
An investigator often starts with a rough sketch and eventually moves on to a final sketch that is drawn to scale. These sketches are commonly employed as models during court hearings and trials because these provide the floor-plan of an area of interest, the elevation of the area and its details and other critical dimensions that may be helpful in the analysis of a crime scene. Physical surveillance serves more purposes in a crime scene investigation than a technical surveillance because it provides the investigator with sufficient evidence that may be important in linking a specific suspect to a particular crime.