Soil analysis. Soil sample being ground up using a pestle and mortar. Various soil samples are seen in the surrounding dishes. The petri dish at upper left has been used to sort soil particles by size and type. The ground up soil in the mortar will be subjected to a chemical analysis. The forensic investigator will examine the soil particles and the soil chemistry, and identify the soil type, as well as characteristics unique to that soil. This can include specific rock types and microscopic plants and animals that are found only in certain areas. When compared to other soil samples, this evidence could help to place a suspect at a crime scene.