IntroductionForensic investigations require an understanding of factors that determine rates of corpse decomposition.

One of the key factors in the decomposition process is temperature.

Understanding corpse temperature throughout decomposition is crucial in determining the post mortem interval (PMI) (Tibbett et al. 2004).

Temperature affects the rate in which a corpse progresses through the 4 stages of decomposition: fresh, bloat, decay and dry (Calce and Rogers 2007).

This research was conducted in order to determine how temperature affects the decomposition rate of a porcine corpse above and below ground.

ObjectivesTo measure temperature variation as decomposition proceeds

To compare the temperature variation of different body regions

To compare the above versus below ground temperature profiles

Methods

Two 27 kilogram porcine corpses were obtained

Temperature probes from a HOBO 4-channel data logger (Onset Computers) were placed in 5 body regions of each corpse: brain, thigh, gut, chest and subcutaneous layer

Corpses were placed either above ground or in a grave 1.2 m deep in clay soil

The temperature of each region was taken every 4 hours for 114 days

The 10,944 temperature readings were uploaded and analyzed using Instat and Prism software

The Temperature of Five Body Regions of a Decomposing Porcine Corpse Above and Below Ground

Lindsey Dieso-Ballesteros1, Joshua Lawrence2, John Levisky2, and Bradley Rehnberg1

Departments of 1Biological and 2Behavioral Sciences York College of Pennsylvania

Results

Figure 1. The mean daily temperatures of the chest region of the corpseabove ground. Each value is an average of the 6 temperatures that wererecorded daily. Error bars represent a 95% confidence interval.

Figure 2. The mean daily temperatures of the brain region of the corpseabove ground. Each value is an average of the 6 temperatures that wererecorded daily. Error bars represent a 95% confidence interval.

Key Points: There is a significant increase in temperatures of the chest and brain region of the above ground corpse whencompared to air temperature between days 12 and 17. The buried corpse exhibited an increase over ground temperature only in the brain region throughout the experiment.

Figure 3. The average daily temperatures of all the body regions of the buried corpse. Each value is an average of the 6 temperatures that were recorded daily.Error bars represent a 95% confidence interval.

Figure 4. The average daily temperatures of all the body regions of the above ground corpse. Each value is an average of the 6 temperatures that were recorded daily. Error bars represent a 95% confidence interval.

Key Points: Each of the buried corpse body regions, except the brain, closely followed ground temperature throughout the experiment. All body regions of the above ground corpse exhibited a significant temperature increase over ambient between days 12 and 17.

Figure 5. Change in temperature (∆T) of the chest region of both corpses in relation to their environment. The above ground corpse values are the difference in chest region temperature and air temperature whereas the buried corpse values are the difference in chest region temperature and soil temperature in the grave.

Figure 6. Change in temperature (∆T) of the brain region of both corpses in relation to their environment. The above ground corpse values are the difference in brain region temperature and air temperature whereas the buried corpse values are the difference in brain region temperature and soil temperature in the grave.

ConclusionsHigher tissue temperatures and maggot activity lead to faster decomposition above ground.

The elevation in brain temperature of the buried corpse was likely caused by brain heat produced by soil decomposers which gained access through the eyes, ears and nose.

The brain region is composed of soft, lipid-richtissues. Other regions consist mostly of muscle and connective tissues. This difference made the brain region prone to higher maggot activitythroughout the experiment (Adlam and Simmons 2007).

Key Points: Throughout the time when maggot activity was most intense the temperature of both the chest and brain regions of the above ground corpse elevated above ambient temperature by 11-13 °C.

Literature CitedAdlam, R. and Simmons, T. 2007. The Effect of Repeated Physical Disturbance on Soft Tissue Decomposition-Are Taphonomic Studies an Accurate Reflection of Decompositoin. Journal of Forensic Sciences 52:1007-1014.

Calce, S. and Rogers, T. 2007. Taphonomic Changes to Blunt Force Trauma: A Preliminary Study. Journal of Forensic Sciences 52:519-527.

Tibbett, M., Carter, D., Haslam, T., Major, R. and Haslam, R. 2004. A Laboratory Incubation Method for Determining the Rate of Microbiological Degradation of Skeletal Muscle Tissue in Soil. Journal of Forensic Sciences 49:560-565.

Acknowledgements

The authors would like to thank Mr. Jake Kint for allowingus to utilize his land for this experiment.

Intense Above-Ground Maggot Activity

Intense Above-Ground Maggot Activity

Intense Above-Ground Maggot Activity

Intense Above-Ground Maggot Activity

Intense Above-Ground Maggot Activity Intense Above-Ground Maggot Activity

Figure 7. Intense maggot activity in the abdominal region of the aboveground corpse.

Mean Daily Temperatures

0 5 10 15 20 25 30

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40Corpse Above Ground ChestCorpse Below Ground ChestAirSoil

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40Corpse Above Ground BrainCorpse Below Ground BrainAirSoil

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All Body Regions of Buried Corpse

0 5 10 15 20 25 305

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GutThighSub q

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BrainSoil

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All Body Regions of Above Ground Corpse

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Chest T

7 9 11 13 15 17 19 21 23-5

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Buried CorpseAbove Ground Corpse

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Brain T

7 9 11 13 15 17 19 21 23-5

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Buried Corpse

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