NCJ Number
221157
Journal
Journal of Forensic Identification Volume: 57 Issue: 6 Dated: November/December 2007 Pages: 823-840
Date Published
November 2007
Length
18 pages
Annotation
This article reports on a method of casting impressions in snow with dental stone that produces impressive results with minimal effort.
Abstract
The dry-casting method with dental stone is useful for several reasons. First, the method uses materials commonly carried by crime-scene investigators, namely dental stone and water. Second, pastry sifters are inexpensive and simple to use. This technique is not adversely affected by cold temperatures and works well on a variety of snowpack conditions. The most important effect of this casting method, however, is the quality of the final cast when compared to the application of dental stone by pouring. Noticeably improved quality is obtained by simply changing the technique in applying the dental stone product. The authors recommend that investigators practice this method prior to using it in actual crime-scene work. Investigators may choose to practice on nearby snowpacks at the crime scene in order to assess such variables as setting time and water content of the snow. This method can be used following highlighting with spray paint. Investigators should be aware that paints or snow-print wax used in highlighting a snow impression will absorb solar heat, which may rapidly melt the impression. If a highlighting spray is used, the authors recommend either the use of a box cover or the timely application of the dental stone product, so as to reduce the effects of direct sunlight on the impression. The authors do not advocate replacing the common use of snow-print waxes with the dry-casting method, since snow-print wax can produce casts with excellent quality; however, dry casting consistently produces better quality impressions over a wide variety of snow conditions. The materials and methods used for the casts depicted in this article's figures are described. 5 figures and 17 references