Investigator Disturbance and Buried Remains: An Experimental Study on Buried Nonhuman Decomposition

The experimental study of buried remains presents a unique set of problems for the investigator. With uncovered remains, visual and non-invasive/non-destructive methods alone can be utilized with no direct interaction between the investigator and the body, and thus allows for the repeated use of that body throughout the study. Usually presented as a group of categories or stages of decomposition, these methods are used as a basis for comparison among the sample and between studies. Buried remains, however, cannot be assessed, either visually or through other methods, without intentional disruption of the grave environment by the investigator. The removal of the soil above the remains, exposure to sunlight, and other above-ground variables are expected to impact the decomposition of the remains. Thus, experimental studies often group their subjects so that a body or set of remains is only sampled once at a predetermined point in the entire study.

In the present experiment, the soil was separated by a cage from six pig carcasses in separate graves in an attempt to limit the amount of investigator disturbance during data collection, and thus assess whether repeatedly exposing remains affected their decomposition and the resulting accumulated degree-days and date-of-placement estimations. Pig 1 had significantly decomposed by the first uncovering 28 days after burial. On day 61, when Pig 1 and Pig 2 were disturbed, it was noticed that Pig 1 had developed decomposition fluid at the foot of its grave while Pig 2’s grave was dry. This pattern continued to an extent throughout the experiment. Throughout the study, the grave walls and the cage containing the soil also became increasingly unstable.

The results indicate that isolating the soil and uncovering the buried remains for assessment will affect decomposition. However, it is unclear whether it is the isolation of the top iv soil or the act of uncovering the remains that caused the different decomposition between subjects. A number of improvements for future studies are recommended.