How Digital forensic photography forensic photography is used in domestic violence cases and convictions Malcolm Washington Governors State University Professor
How Digital forensic photography forensic photography is used in domestic violence cases and convictions
Governors State University
Professor (Nuke) NkulenuAbstract
Photography is what people use to take pictures and preserve past visual memories. Past memories can be preserved with cameras. Cameras can take video or still pictures of anything that it important to you. Using instant photography for digital forensic photography is important to preserve evidence of visual facts.
Instant camera film is just as much the same as regular camera film but with a few extra elements.
In 1947, an inventor named Edwin Land introduced a remarkable innovation to the world — a film that developed itself in a matter of minutes. This new instant camera technology was a huge success for Land’s company, the Polaroid Corporation. In 1949, Polaroid made more than $5 million in camera sales alone! Over the proceeding 50 years, the company carved out its own special niche, selling millions of instant cameras and more than a billion rolls of instant film (https://en.wikipedia.org/wiki/Polaroid, paragraph embedded).
There are basically three common types of film: black and white film, color film and transparency film. Film has varying degrees of sensitivity to the amount and intensity of light. These degrees of sensitivity are referred to as the American Standards Association. The higher the ANSI number the “faster” the film. Faster film reacts quicker to light; therefore, it requires less light for proper exposure.
The basic idea of film is to capture patterns of light using special chemicals. The camera briefly exposes the film to the light coming from a scene and where the light hits the film, it starts off a chemical reaction.
Print film consists of a plastic base that is coated with particles of a silver compound. When this compound is exposed to many light photons, it forms silver atoms. Black-and-white film has one layer of silver compound, while color film has three layers. In color film, the top layer is sensitive to blue light, the next layer is sensitive to green and the bottom layer is sensitive to red. When you expose the film, the sensitive grains at each layer react to light of that color, creating a chemical record of the light and color pattern.
To turn this into a picture, you must develop the film using more chemicals. One chemical developer turns the exposed particles into metallic silver. The film is then treated with three different dye developers containing dye couplers. The three dye colors are: Cyan, Magenta, and Yellow.
Each of these dye-coupler types react with one of the color layers in the film. In ordinary print film, the dye couplers attach to particles that have been exposed. In color slide film, the dye couplers attach to the non-exposed areas.
Slide film has accurate color rendition, it lacks latitude. Latitude in photography is the ability to produce a good picture from a negative that is slightly underexposed or slightly overexposed. The corrections can be used to print film through adjustments in the print processing. Slide film is not designed for print processing and thus lacks latitude. This means that the exposure must be exact for the photo to turn out correctly.
Developed color film has a negative image — the colors appear opposite of the colors in the original scene. In slide film, the two dyes that attach to the unexposed area combine to form the color captured at the exposed layer. For example, if the green layer is exposed, yellow and cyan dye will attach on either side of the green layer, but the magenta dye will not attach at the green layer. The yellow and cyan combine to form green.
Print film also offers considerable latitude in exposure, it provides a definite advantage for those who are not expert photographers. Because documentation of evidence requires the reproduction to be as accurate as possible, color film is the best medium.
In domestic violence photography, UV and IR techniques are often used to see images that our eyes cannot see. These techniques are useful because of the way our skin interacts differently with UV and IR light compared to visible light. For these techniques black and white film offers the best results.
There are two reasons for this. First, the top emulsion layer of all color film which is blue, contains UV blockers preventing the exposure of the bottom layers. Second, the blue layer that does react does not provide as much contrast as black and white film. In addition, there is no “color” in the UV and IR region, so nothing is gained using color films.
It should also be noted that special IR film is needed for IR photography. Normal black and white film is not sensitive to the near IR region. IR film is sensitive from the IR region to the UV region and may be used for both techniques.
The instant-camera developing process combines colors in the same basic way as color slide film, but the developing chemicals are already present in the film itself.
Though the quality of integral instant film is not as good as conventional film, peel apart black and white film, and to a lesser extent color film approached the quality of traditional film types. Instant film was used where it was undesirable to have to wait for a roll of conventional film to be finished and processed, e.g., documenting evidence in law enforcement, in health care and scientific applications, and producing photographs for passports and other identity documents, or simply for snapshots to be seen immediately.
Finally, I bring photography, domestic violence and instant film together for use in forensic photography. Forensic photography, also referred to as crime scene photography, is an activity that records the initial appearance of the crime scene and physical evidence, to provide a permanent record for the courts. Crime scene photography differs from other variations of photography because crime scene photographers usually have a very specific purpose for capturing each image.
The body can be a major source of physical evidence that is used to associate or link suspects to violence. It is the basis of why the violated body of domestic violence should be investigated. Any damage found on the human body can be physical evidence. In a scientific police investigation, the first activities of the police are to photograph essential damage to the body for the successful preservation of the physical evidence using instant photography. The first responder and ultimately the police have the obligation to make the domestic violence victim feel secure and ensure that any further activities between the victim and offender do not change the evidence.
Proper photo documentation when using instant photography in domestic violence cases is crucial in establishing the chain of evidence needed to prosecute cases. It helps prosecutor’s secure early guilty pleas from offenders, reducing court costs and caseloads.
Instant photo documentation in forensic photography helps increase domestic violence conviction rates. When using instant photo documentation cases can be successfully prosecuted without the victim’s testimony because bruises fade with time, but instant photos depicting injuries do not. Instant photos are also tamper resistant. Police and law enforcement officers can see immediately that the right image was captured, minimizing the number of photos taken per case. One-on-one or close-up photos of victim’s injuries, and close-up or mid-range imagery that includes the victim’s face for identification purposes, can show indications of past abuse such as scars, or faded bruising which could be evidence of abuse over an extended period. Instant photo documentation in forensic photography can provide evidence before officer leaves the scene and photos can become part of the case file immediately, particularly important for fast arraignments. Police also use instant photography for forensic uses to document the scene of the violence by taking pictures of broken furniture, or any damage to personal property of the victim. They can show the severity of the violence and they can show any violence against children, showing them crying, scared, upset or injured.
These photos can be uploaded to a website such as https://www.docx.us/ which allows police and law enforcement to create high-res Polaroid photos and then they can be stored digitally for further and closer examination.
Polaroid Corporation has an active market in forensic domestic abuse photography. These systems work well when instant results are necessary. However, the color balance is not comparable to print film, and either duplicates or enlargements must be made by re-photographing the Polaroid picture with print film. Despite its shortcomings, the simplicity of the instant camera may be critical if the alternative equipment and necessary skills are not available.
More than 100,000 police officers in the world report using Polaroid cameras to document domestic violence injuries.
This paper is not about instant photography but how it can be use in domestic violence cases in regards to forensic photography to prosecute cases and get convictions.References
U.S Justice Department,