NCJ Number
218756
Date Published
April 2002
Length
4 pages
Annotation
This paper describes the proper documentation of latent print evidence in the field using a digital camera.
Abstract
Three procedures are enumerated: (1) lens calibration to achieve a minimum of 1,000 pixels per inch (ppi); (2) camera set-up for latent impression photography; and (3) use of a portable computer in field operations to acquire file/images. Equipment recommendations are offered and include the advice to have a professional digital camera kit that consists of items such as a dedicated electronic flash and flash cable, remote shutter release, tripod capable of various angles and positions, and a professional digital camera with interchangeable lenses. A portable computer dedicated only to field use is also necessary and general requirements for the portable computer are offered. The first procedure for photographing latent impressions using a digital camera involves calibrating the lens to achieve a minimum of 1,000 ppi. Eleven step-by-step instructions are presented for this process. In the second procedure, the camera setup is described, which follows 15 steps such as visually verifying the images, lighting visible impressions appropriately, and adjusting camera settings to the light meter reading. The third procedure includes seven steps on how to use a portable computer in field operations to acquire file or images. The recommendations were made in accordance with National Institute of Standards and Technology (NIST) guidelines that specify 1,000 pixels per inch at a 1-to-1 ratio.