User:Kristinapham/Forensic photography

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Forensic photography may refer to the visual documentation of different aspects that can be found at a crime scene. It may include the documentation of the crime scene, or physical evidence that is either found at a crime scene or already processed in a laboratory. Forensic photography differs from other variations of photography because crime scene photographers usually have a very specific purpose for capturing each image. As a result, the quality of forensic documentation may determine the result of an investigation, in that with the absence of good documentation, investigators may find it impossible to conclude what did or did not happen.

Crime scenes can be major sources of physical evidence that is used to associate or link suspects to scenes, victims to scenes, and suspects to victims. Locard's exchange principle is a major concept that helps determine these relationships. It is the basic tenet of why crime scenes should be investigated. Anything found at a crime scene can be used as physical evidence as long as it is relevant to the case. In scientific crime scene investigation, the first activities at the crime scene are essential for the successful preservation of the physical evidence. The first responder and ultimately the crime scene investigator have the obligation to make the scene secure and ensure that any further activities at the scene do not change the evidence. The use of a multilevel security method would accomplish this task. The preliminary scene survey is the first on-scene activity. Precautions are taken for transient and conditional evidence during the survey.

Knowing that crucial information for an investigation can be found at a crime scene, forensic photography is a form of documentation that is essential for retaining the quality of discovered physical evidence. Such physical evidence to be documented include those found at the crime scene, in the laboratory, or for the identification of suspects.

All forensic photography must consider three elements at a crime scene: the subject, the scale, and a reference object. Also, the overall forensic photographs must be shown a neutral and accurate representation.

Crime scene photography
Common types of photography such as creative and artistic photography give a different purpose than forensic photography.

Crime scene photography allows us to capture essential aspects of the presented from the crime scene, including its scope, the focal points of the scene, and any physical or material evidence found at or from a result of it. With the use of crime scene photography, the context of the crime scene can be represented through a series of photographs; aiming to tell the whole story. Such photographs are used to capture the physical environment of the scene and its surroundings, in addition to physical evidence in situ and key areas of the crime scene (e.g., entrances and exits). Moreover, these photographs may be taken at various ranges depending on the content that is being captured. For example, physical evidence (e.g., footprints, wound details, trace evidence, etc.) may require close-up images, whereas the conditions of a room may only require overall and/or midrange photography. Photographs may also be supported with video recordings.

Evidence photography
This form of photography is to provide images of the varying types of physical evidence and used as evidence in court, part of the case record, or by other investigators ; typically of forensic findings during the analysis of various forensic disciplines. Forensic laboratories generally use infrared, ultraviolet (UV), x-ray, or laser radiation in addition to cameras and microscopes, to represent details that would otherwise be invisible to the naked eye. However, it is crucial that such details do not interfere with the appearance and condition of the evidence being documented.

To ensure quality photographs, general evidence is documented under the following conditions:


 * 1) The evidence is placed on a clean and distraction-free background (i.e., background paper, butcher paper, neutral countertop, etc.).
 * 2) Even illumination. This can be achieved with two light sources of equal power and distance, placed approximately 45 degrees toward the evidence.
 * 3) The camera should be placed directly overhead of the evidence. A ladder or scaffolding may be required for larger items.
 * 4) Case number and scale present in all photographs.
 * 5) All sides of the evidence photographed
 * 6) Close-up photographs of relevant details found on the evidence.

Impression photography
Photographs of impressions such as fingerprints, footwear impressions, and tool marks require certain standards as they may be analyzed, compared, and searched through a large digital databases. For example, fingerprints are often entered into the Automated Fingerprint Identification System (AFIS). To meet the standards for such material evidence, they must:


 * 1) Fill the frame with the impression to take advantage of the camera's resolution;
 * 2) Include a scale for accurate calibration;
 * 3) Have parallel planes of the subject, scale, and image;
 * 4) Be in sharp focus and exposed correctly; and
 * 5) Have even illumination of the area of interest.

In addition, it is suggested that these impression images be recorded in camera RAW, although the photographer may decide to edit via Photoshop or another editing software. That will create a TIFF image, but increase the quality of the image.

Mug shots
Mug shots are taken for individuals who have been charged with a crime, and once one is created, it is automatically entered into a master database with any existing information on that individual. To maintain consistent quality, standardized lighting, background, and distance is required. In addition to associating filed information, physical features (e.g., hair and eye colour, facial hair, tattoos, etc.) is also associated and appropriate is a photo line-up is required.