NCJ Number
187599
Journal
Law Enforcement Technology Volume: 28 Issue: 2 Dated: February 2001 Pages: 98-100
Date Published
February 2001
Length
3 pages
Annotation
Innovations in close-range photogrammetry make it possible for investigators to make unlimited, high-accuracy measurements at crime and accident scenes directly from the standard photographs taken at the scene.
Abstract
Forensic photogrammetry refers to the making of 3-D measurements of the real world directly from photographs for use in courts of law. Close range refers generally to ground-based photography, not aerial photography. The photogrammetric measurements are made in the office or lab after the scene is photographed, so there is little impact on the investigator processing the scene. Photogrammetry can accurately locate and measure any object appearing in two or more photographs. Because anything in the pictures can be measured, the scene is effectively preserved and can be "revisited" at any time. Photogrammetry can automatically orient photographs taken from awkward angles and correct for camera misalignment. Further, with accurate measurements generated easily, the scene can be reconstructed as a computer model, with all spatial relationships intact and available for presentation in court. This article discusses the admissibility of such exhibits in court, how to photograph crime scenes with measurement in mind, the measurement of a digitized scene, and special applications of digital photogrammetric techniques (blood splatter analysis, explosion analysis, and 3-D tool mark examination).