Alternate Light Sources (ALS) are tools that can permit investigators to locate, process, and photograph otherwise invisible evidence. Understanding how these devices work is helpful in applying them correctly at the crime scene or in the laboratory. This course begins with a discussion of the properties of light and luminescence and culminates in the use of the ALS to visualize and photograph items of evidence. A review of basic photography and the use more advanced photographic techniques to optimize image quality will be included.
The types of evidence on which ALS units are commonly utilized include fingerprint evidence, trace evidence (like hairs and fibers, narcotics, gunshot residue, and body fluids), and bodily injuries. In-class hands-on exercises will include all of these types of evidence. This course will heavily emphasize instruction using hands-on techniques. The students will photograph realistic evidence to observe the photographic results of the techniques learned and used in class.