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No attempt should be made to remove soil from clothing, footwear or tires. If these items can be removed intact they should be placed in a paper bag or enclosed in a druggist's fold and then placed in a paper bag. Care must be taken so that the paper bag is protected so that evidence is not lost through holes in the bag. Some evidence can be placed in plastic bags but is must be completely dry. Wet samples placed in plastic with quickly degrade and rot and become useless. Plastic does not "breath" to allow passage of moisture and air. Paper on the other hand will allow moisture to escape preventing rot.

Lumps of soil stained with blood, semen or other biological samples should be collected intact and transported to the lab as dry samples. Any samples containing suspected biological material such as blood, flesh, semen or hair must be clearly labeled so that the analyst at the lab can take precautions to preserve this material. Biological specimens in soil must never be heat dried.

The only time a sample should not be allowed to dry is when insect evidence such as maggots are present. In the case of maggots there is a very specific way of handling this evidence. Samples containing maggots can be placed in aluminum foil with a small piece beef liver and placed in a plastic container. There must be air available in the container. These samples must be sent to the lab immediately. The specimens can be placed in a thermally protected case such as a cooler. Attempts should be made to protect the samples from extremes of heat and cold. Never use dry ice with biological or entomological (insect) evidence.

In the Laboratory

In the lab items from the victim and suspect should be examined separately.
Ideally the items and samples from the victim and suspect should be processed in different rooms. The personnel handling these sample should be assigned to one or the other. If this is not possible then the person handling the material should take extreme care to avoid cross contamination of the samples.

The laboratory staff will evaluate the soil samples in several ways. First the mineral content will be tested. Some experienced analysts can moisten a sample and feel the soil. Based on feel alone they can tell the ratio of mineral and organic content. Microscopic examination of soil samples will subsequently reveal the type and nature of the mineral, biological and synthetic content of a sample.

Such talented analysts are not always available. Then, there are several standard

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