Soil samples in a petri dish for forensic analysis and comparison. The compartments of the petri dish have been used to sort the soil particles by size and type. The forensic investigator will examine the soil particles 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 and evidence, such an analysis can help to place a suspect at a crime scene.