PHYSICAL EVIDENCE MANUAL - Crime Scene Investigator Network

Physical Evidence Manual
Casting Methods
Adopted: May 2002
Revisions: 6
Last Revision: January 31, 2008
Figure 6: Representation of the camera and
tripod setup for shoeprint photography
Dental stone or die stone should be used to cast footwear and tire tread
impressions in soil and sand. Plaster of Paris is no longer recommended as an
acceptable casting material. Dental stone can be obtained from local dental
supply houses or in pre-made ready to use kits at minimal cost.
If using bulk dental stone, two (2) pounds of dental stone may be placed into an
8x12 inch Ziploc plastic bag; this amount will cast an average sized shoe
impression. In preparation for use at crime scenes, numerous two-pound bags
can be prepared and stored.
When using a commercially prepared kit, follow manufacturer instructions for
mixing. The following is the procedure for making a cast from a self-made dental
stone kit:
1. Retrieve a two-pound bag, add about 10 ounces of water, and thoroughly
mix in the closed bag. The mixture should have the consistency of thin
pancake batter. If needed, add more water or dental stone to create the
correct consistency.
2. Open the bag and with the bag at ground level, carefully pour the mixture
into or next to the impressions, allowing it to gently flow into it. Fill the
impression completely so that the mixture overflows out of the impression.
3. When the cast is firm but still soft, scratch identifying marks on the
exposed surface or write identifying marks with a permanent marker when
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