Crime scene

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"Crime Scene" redirects here. For other uses, see Crime Scene (disambiguation).
A crime scene

A crime scene is a location where a crime took place (or another location where evidence of the crime may be found), and comprises the area from which most of the physical evidence is retrieved by law enforcement personnel, crime scene investigators (CSIs) or in rare circumstances, forensic scientists. Crime scenes may or may not be where the crime was committed. There are different levels and types of crime scenes.

Crime scene preservation[edit]

A perimeter is taped off with barricade tape in order to keep only those necessary on site. This is done to preserve evidence of the crime.

Documentation[edit]

Photographs of all evidence are taken before anything is touched, moved, or otherwise further investigated. Evidence markers are placed next to each piece of evidence allowing for organization of the evidence. Sketching the scene is also a form of documentation at a crime scene. This allows for notes to be taken as well as to gauge distances and other information that may not be easily detected from only a photograph. The investigators will draw out locations of evidence and all other objects in the room. The sketch is usually drawn from an above point of view. Notes are taken by investigators to ensure memorization of their thoughts and suspicions about different pieces of evidence.

Evidence collection[edit]

Evidence is collected through two ways: forensics and interviews. All forensic evidence is bagged separately to prevent any cross-contamination. Forensics uses a variety of different tools and techniques. Fingerprint collection through the use of grey or black magnetic powder. DNA and other bodily fluids are collected and, whether it is hair or fluid, for further examination in a lab. Shoe and tire prints can be collected using dental stone. Electronics are taken for examination by a technical expert to search for further evidence. Documents from the area are also taken for further examination. Ammunition and weapons are taken for matching to wounds and ballistics. Photographs of tool marks are taken because they can be matched to a weapon at a later time. Any other trace evidence is also collected. Trace evidence is anything left behind by a perpetrator or could have been transferred to the perpetrator. Interviews of both witnesses and victims of the crime are taken by law enforcement officials in order to gain knowledge and creating a timeline of events.

Types of crime scenes[edit]

Different types of crime scenes include outdoors, indoor, and conveyance. Outdoor crime scenes are the most difficult to investigate. The exposure to elements such as rain, wind, or heat, as well as animal activity, contaminates the crime scene and leads to the destruction of evidence. Indoor crime scenes have a significantly lower chance of contamination because of the lack of exposure. The contamination here usually comes from the people factor. Conveyance crime scenes are crimes committed by means of transportation, such as robbery or auto theft. Each type of crime scene, along with the nature of the crime committed (robbery, homicide, rape, etc.) have different procedures.

Reconstruction[edit]

Crime scene reconstruction is the use of scientific methods, physical evidence, deductive reasoning, and their interrelationships to gain explicit knowledge of the series of events that surround the commission of a crime.

See also[edit]

External links[edit]