NCJ Number
182154
Journal
Journal of Forensic Sciences Volume: 45 Issue: 2 Dated: March 2000 Pages: 333-348
Date Published
March 2000
Length
16 pages
Annotation
This article reports on six test firings of large improvised explosive devices; the primary objectives of the firings were to measure the physical effects of the explosions upon representative objects placed nearby and to recover any chemical traces deposited on these objects.
Abstract
The results are intended for use as an aid in determining the approximate size and type of an explosive used in terrorist attacks. Three 454 kg charges of a mixture of calcium ammonium nitrate (CAN) fertilizer and sugar, and three 2,268 kg charges of a similar mixture, all confined in cylindrical steel containers, were fired. Each charge was surrounded by 19 road signs mounted on posts and four vehicles, to act as witness materials. The analysis of aqueous swab extracts taken from the witness materials after firing showed the recovery of nitrate, ammonium, and low levels of glucose. No sucrose was detected. Nitrate was usually recovered in greater quantities than ammonium, and recovery generally decreased with increasing distance from the charges in any given direction. Quantities recovered from objects placed at the same distance in different directions varied considerably. Patterns of physical damage to the witness materials could be discerned according to their distance from the charge and the size of the charge. The velocities of detonation and air blast effects were measured. 17 figures, 17 tables, and 1 reference