ABSTRACT
Many objects, when illuminated with alternate light sources (ALSs), will fluoresce; that is, they will emit light at higher wavelengths. ALSs are thus commonly employed by crime scene investigators (CSIs) in an attempt to locate evidence that would otherwise be invisible to the naked eye. This chapter provides simple instructions regarding how to photograph evidence illuminated with an ALS. To properly photograph evidence fluorescing from an ALS, investigators will generally require low light conditions. So a tripod and slow shutter speed will be mandatory. Both UV and infrared wavelengths are sometimes used to locate physical evidence. UV may be helpful in locating a wide array of evidence, although caution is advised due to its harmful effects upon deoxyribonucleic acid (DNA). Infrared light can be used to detect different inks and writing on burned documents and has been reported as being useful in photographing bruises. Most cameras are not equipped to capture infrared light-illuminated evidence.
