Soil Traces as a Source of Meaningful Criminalistic Information (on examples of soils from Moscow region).

Laboratory of Forensic Soil and Biological Science (LFS&BS) of the Russian Federal Centre of Forensic Science at the Ministry of Justice of the Russian Federation is one of the oldest in the forensic science system in Russia. It was founded more then 35 years ago. Formerly and nowadays the bulk of forensic soil examination are dealing with enormous and highly enormous offences (murders, robbery-related homicides, sexual assaults, etc) and more seldom with thefts.

Soil traces on different subjects (object-carriers) are under investigation with the aim of getting important information in inquiring of criminal cases which happen on the territory of Moscow region (including Moscow and its suburb and some neighboring regions in the radius of about 200km from Moscow).

Moscow region rocks have the glacial or post-glacial origin and are characterized by trivial associations with minimum perceptible difference of sandy-clay and clay fractions of soil minerals.

The largest part of soils is tilled and the degree of cultivation increases from north to south. There is an extended river network with a wide valley areas of reach alluvial soils greatly cultivated.

On the east there is a spacious massive of sands covered by peat swamps. Sediments risen on the top of the earth and anthropogeniс soils are also widely abounded in Moscow region. 

Undoubtedly, that forensic soil scientists widely use knowledge, accumulated by Russian Dokuchaev`s soil scientist school when examining soil traces. Nevertheless soil investigation in the aim of forensics has its own peculiarities (specific features).

We would not talk here about a small quantity of soil traces which is very common for forensic soil examination, it should be only mentioned that soil scientists investigate soil as a natural complex/ensemble of genetic horizons (so called soil profile), while an object of forensic soil scientists is investigation of soil traces which could be represented by only one genetic horizon or could be a mechanical mixture of different genetic horizons or artificial (anthropogenic) soil layers. So forensic soil scientists are dealing with investigation of separate parts of soil profile, or so called “soil matter”, taken from different parts of soil profile. Also forensic soil scientists are dealing with investigation of “soil matter” taken from different types of soils, parent rocks and anthropogenic soil layers, sediments and so.

We would like to demonstrate ways of obtaining meaningful criminalistic information when proceeding investigation of soil traces when they are a mechanical mixture of “soil matter” from different soil horizons. Such information could be helpful for police officer or inquiring officer in solving concrete criminal investigation.

Obtaining of meaningful criminalistic information during forensic soil examination is realized by solving two principal tasks.

 The first task is establishment the fact of a person (object) being on a defined place important for criminal case proceeding - comparative studies.

The second task is a search of a place (usually crime scene) inside a given territory important for criminal case investigation - provenance determination.

These places are usually situated on territories with natural soils with an undisturbed (or disturbed) structure, with (or without) additional anthropogenic contamination.

Soil substance - synthetic in its nature, can be specified by three groups of independent attributes/characteristics.

1. Soil characteristics occurred as the result of pedogenesis process (texture, color, new formations, specific organic matter)
2. Parent rock characteristics (mineral content of sandy-clay fraction, granulometric composition)
3. Phytocenosis characteristics: litter fragments, fragments of green plants, pollen and spores, diatoms, phytolites

The fourth group - a complex of anthropogenic contaminations should be added, when soils are influenced by anthropogenic activity of people.

More meaningful information could be obtained when there are more charcteristics reflected in soil traces.

Best of all it could be illustrated on examples from our experience of forensic soil examination of murder and theft cases when the soil traces on the objects under investigation occurred as a result of pit digging in different places with different types of soil, landscape and phytocenosis.