ABSTRACT
Every crime scene represents an individual challenge. Each has its own unique problems and its own unique issues, and the scene technician must meet these with a mixture of skill and knowledge, all the while employing a healthy dose of flexibility. Beyond these unique challenges, within almost every crime scene, the technician will encounter basic evidence-recovery issues. The skills needed to meet and resolve these problems include using light technology, recovering fingerprints, and casting a wide variety of impressions. The chapter describes basic light technology. Alternative light sources (ALSs) allow the crime scene technician to employ a variety of narrow wavelengths of the light spectrum in an effort to identify, visualize, and document a variety of different types of physical evidence. Near-UV and violet light serve a variety of functions in the crime scene. Most ALS systems also have a crime scene search setting, but these are often a more discrete blue/cyan wavelength.
