Document impression with appropriate photography before initiating any casting.
Surround impression with metal or wooden frame. Press frame into the ground surrounding the impression.
Combine dental stone casting material and water in a mixing container (disposable plastic bag is recommended). Continue to add water and combine the mixture until you reach the consistency of pancake batter.
Slowly pour casting material inside the frame surrounding the impression. Don’t pour the casting material directly onto the impression, pour it in slowly from one of the corners until the casting material covers the impression about a half inch.
Allow the casting material to dry completely. Once dry, it will be hard to the touch.
Collect the cast and package it securely inside a box. Dirt can be brushed away from the surface of the cast with a soft bristled brush.
REFERENCES
Bodziak, William (2000). Footwear Impression Evidence, Detection, Recovery and Examination. CRC Press.
Bodziak, William (2008). Tire Tread and Tire Track Evidence: Recovery and Forensic Examination. CRC Press.
Dutelle, Aric (2020). An Introduction to Crime Scene Investigation. Jones & Bartlett Learning.
Fish, Jacqueline et al (2014). Crime Scene Investigation. Routledge.
Fisher, Barry & Fisher, David (2012). Techniques of Crime Scene Investigation. CRC Press.
Gardner, Ross & Krouskup, Donna (2018). Practical Crime Scene Processing and Investigation, Third Edition. CRC Press.
Maloney, Michael & Housman, Donald (2014). Crime Scene Investigation Procedural Guide. CRC Press.
Ramirez, Christine & Parish-Fisher, Casie (2011). Crime Scene Processing and Investigation. CRC Press.