His presentation, "Photographing and Casting Snow Impression Evidence," will review techniques for photographing and casting snow impressions; the use of sprays and oblique light to enhance contrast on different types of snow for photography; and the use of dental stone, fast setting plaster, and sulfur cement casting and type of snow and weather conditions.

Left: Valdez Police Dept. officers in Prof. Wolfe's training class work on collecting snow impression evidence.