How It’s Done
Who Conducts the Photographic Analysis and Enhancements
Once working copies of all the photographs have been created, investigators can select images for analysis and enhancement. This is normally done by the photographer or, if available, within the audio/visual department in the laboratory. As with all evidence, detailed records should be kept regarding who accesses or works with the files and what techniques were used to enhance or otherwise modify the files.
The International Association for Identification (IAI) has a Certified Forensic Photographer (CFPH) program, established in 2001. The CFPH process is accredited by the Forensic Specialties Accreditation Board. This program requires specific training or coursework and testing that includes both written and practical assessments. Evidence Photographers International Council (EPIC) formerly provided specific certification for evidence photographers.
Many times, the images are taken by a member of the investigative team that is responsible for many crime scene duties that also incorporates photography. Depending on the size of the agency and support from their local laboratory, more experienced photographers may be available for major cases.
How and Where Evidence Photographs are Processed
The majority of evidence photography is now done using digital cameras and equipment. All photographs taken are saved as originally captured, entered into evidence inventory and tracked. Selected photographs of particular evidence or parts of a scene may need additional enhancement. This can be done within the department if the appropriate software is available or may be sent to a regional specialist. The most common enhancements include cropping, brightness and contrast adjustments and color processing.
Potential photographic enhancements follow the same rules as news journalism. An image may be lightened and darkened, cropped or the color enhanced. The white balance can be adjusted, but adding or removing information is unacceptable. When submitted for courtroom use, the original photograph must be available for comparison and the technician or examiner must be able to show and describe any enhancements that were done and why.
When images are presented, they must be clearly identified as a working and/or enhanced version. The original camera sequential numbering system should be retained to show that images are in order and none have been removed. The working images should not be renamed until identified or selected for use, and original files should not be renamed at all.
Type of Equipment Used
Investigators and technicians photographing a crime scene should have access to a good quality camera that is capable of manual override and has interchangeable lenses, off-camera flash, cable release, and a tripod mount. With these tools and a widely attainable level of training and practice, good quality photographs can be taken in a broad range of scenarios including low light, highly reflective surfaces and tight spaces.
That said, many first responders are equipped with basic, consumer-level point-and-shoot cameras. Since they may be in the best position to capture important evidence, basic knowledge of how to capture an image and use the camera they have is very important. Even with simple equipment, a first responder with introductory photography training can produce images of sufficient quality to support an investigation.
Cellular telephones and other personal electronic devices with integrated cameras are not recommended unless their use is an operational necessity. An example would be if a muddy shoe print is found near a crime scene but it is raining. The shoe print may disappear quickly, so if a cell phone camera is the only camera available, then it would be operationally necessary to use it.