There is a hierarchy of photographs that begin with ‘selfies’ at the bottom of the ladder and ascend in importance until you reach crime scene photography at the top.
But unlike ‘selfies’, crime scene photography has been around almost as long as the first camera. Once police figured out that a photograph could essentially freeze time and preserve evidence, men like the French photographer, Alphonse Bertillon figured out that a systematic approach with multiple angles, including overhead views of a scene would be very helpful to criminologists.
Today, hundreds of photographs will be taken of every crime scene, including pictures of blood pools that will soon be cleaned up, the location of objects and bodies which will eventually be moved, and close-ups of miniscule clues that soon disappear.
Procedure to a higher standard
Photographs (both made from film and created with a digital camera) can be both prejudicial and easily manipulated; therefore the burden of proof of a forensic photograph is to prove that they are what they say they are. It takes testimony to provide the two basic requirements for a photograph to be admissible; relevance and authenticity.
In the field, the primary technique is to follow a procedure. Do it the same way each time, and it is unlikely that an important angle will be missed. Commence with establishing shots; the house, the property, the landscape … as you step into the scene, capture eye-level shots from the viewpoint of the first responder, (after interviewing that person about what happened and if anything has been moved or changed). Find each corner of the scene and shoot several general photos from each. Next, focus on the important details; the body (or bodies), the weapon, blood spatter, broken things, recording proximity and taking care to find relationships and between items.
The facts, Ma’am, nothing but the facts
Attach the close-up lens and look for small details; blood under fingernails, wounds, bullet casings, a bloody knife, whatever is critical to telling the story of the event.
Some items (shoeprints, scuffs, broken glass, tire marks) should be photographed both in their pristine condition and then with a ruler next to them for scale. When shooting with a ruler, try to shoot perpendicular, so that perspective does not change the dimensions when admitted in court.
Good lighting is important for revealing detail and texture. Flashes can be mounted on the camera or on a cord and held away from the lens to reveal detail with shadow. Tripods allow a camera to be held in one place for a series of photographs or to avoid vibration on long exposures. Normal lenses (or slightly wide angle) provide what is considered a ‘normal’ view without distortion seen with extra wide or extra-long telephoto lenses.
The next phase is critical. Paperwork. A report must be written to describe the procedure and any observations. The film or memory cards need a chain of custody form attached, so that they can be vouched for from the moment they are created until they are used in the trial. The photographer will likely be required to testify about how the photos were made and how the images were safeguarded.
Equipment; don’t show up without the ‘right stuff’
The most important part of a photographer’s inventory is skill. Familiarity and comfort with whatever equipment they brought along is critical to taking excellent photos efficiently and accurately.
A good camera kit will start with the basics – one or two professional or high quality consumer-grade cameras, a flash and tripod, additional fully charged batteries for cameras and all electronic equipment. Key equipment also includes a notebook, perhaps a voice recorder for oral notes, rulers for inserting into shots for scale, evidence markers, a few extra flash memory cards, and familiarity with the operation of all devices by the photographer.
As the camera operator runs into challenges, he or she will start adding specialized gear to the camera bag, as needed. A boom arm to extend the camera above the scene to get bird’s eye shots, a ring flash for close-up photography, an extra wide angle lens to get shots inside tight spaces, and so on.
The important thing is to have a complete set of reliable equipment and the peripherals in order to capture the basic requirements without interruption. Dead batteries, lack of memory cards, missing cords, other seemingly minor things can stop a procedure in its tracks.
The digital age; can computer images be trusted?
Whereas the Nikon 35mm film camera with a flash and a couple of lenses was the mainstay of police departments and crime scene investigators world-wide, the rise of digital cameras has now essentially replaced film cameras as budgets are tightened and expectations are increased. It is less restrictive to go to a scene and not worry about film, processing and printing costs. More images are taken, and more angles are possible resulting in more reliable evidence.
There are a couple of things to know about digital photography that become important when creating an exhibit list; first, never delete or erase an image, no matter if it is out of focus o not useful. A digital camera numbers every image it takes, therefore ‘lost’ images leave gaps in the numbering sequence, and therefore raise questions about what may be ‘hidden’ or ‘redacted’.
Secondly, even though digital data has the possibility to be edited and manipulated with sophisticated programs, it also retains qualities that can prove that the raw image is authentic; one characteristic feature of a digital file is that it contains information about itself on hidden headers and tables within the code. These descriptors can prove that an image is original or different.
While photos can now be taken at the scene by a high resolution camera in a smart phone, procedures still need to be adhered to in order to produce images that will not be questioned in court.