Systematic approaches for soil analysis in forensic investigation

In forensic science, soil can be one of the valuable evidence during investigations. Soils might link an individual to a crime scene as soil transferred in a mud stabbing to footwear, tires, soil marks on vehicles, traces left on clothes can correlate the presence or absence of this person on a particular scene of the crime. The soil has extreme complexity not only in components but also in physical nature such as sediment, color, and structure. The aim of the present study was to investigate various physico-chemical properties of different types of soils. These soil properties can be beneficial in forensic investigations along with other evidences found in a crime scene. A number of experiments have been performed to achieve our goal. Particle Size Distribution Analysis PSDA was performed to differentiate between several soil samples based on their texture, through estimation of the size fractions of clay, silt and sand. A hydrometer method was used to estimate the percentages of sand, silt and clay in six samples of soils. We could allocate the soil samples to a textural class that helped us to define the type of soil and link this to a special location. Several soils were analyzed for organic matter content, ammonium, nitrate, carbonates, bicarbonates, chloride, calcium and magnesium in the soil samples. The high variability in results among the tested samples could refer to a unique fingerprinting for each soil type which is vital findings for forensic soil investigations in a crime scene.