Best Practices for Forensic Image Analysis
Scientific Working Group on Imaging Technology (SWGIT)
See also the instructional videos on "Crime Scene and Evidence Photography"
Objective
The objective of this document is to provide personnel with guidance regarding practices appropriate when performing a variety of analytic tasks involving images, regardless of the knowledge domain that is the subject of analysis.
SWGIT Position On Forensic Image Analysis
Forensic image analysis is a forensic science. It has been practiced since the early days of photography, dating at least to 1851 when Marcus A. Root conducted the first documented example of Forensic Image Authentication. Through microscopic examination, Root revealed that the color daguerrotype “process” promoted by Reverend Levi Hill was actually the product of hand coloring, not a breakthrough in photographic science (Davis, Photography, Brown & Benchmark, 1995). In addition to being an accepted scientific practice in the forensic community, image analysis is also recognized in other disciplines including medicine, intelligence, geology, astronomy, agriculture, and others.
Introduction
Forensic Image Analysis is the application of image science and domain expertise to interpret the content of an image and/or the image itself in legal matters. Major subdisciplines of Forensic Image Analysis with law enforcement applications include: Photogrammetry, Photographic Comparison, Content Analysis, and Image Authentication.
The process of Forensic Image Analysis can involve several different tasks, regardless of the type of image analysis performed. These tasks fall into three categories: Interpretation, Examination, and Technical Preparation. These tasks are described below. The general principles and procedures used in these tasks are the same regardless of the format or media in which the images are recorded. Therefore, in this document the word “image” refers to any image recorded on any media (e.g., conventional photographic, electronic, magnetic, or optical media, etc.).