Modeling Temperature Variations Using Monte Carlo Simulation: Implications for Estimation of the Postmortem Interval...

Area of Science:

• Forensic Entomology
• Insect Development Modeling
• Postmortem Interval Estimation

Background:

• Insect development is strongly linked to temperature, a key factor in forensic entomology.
• Accumulated degree-day (ADD) models are standard for estimating insect development, but temperature variations are critical.
• Understanding temperature's impact on insect evidence from death scene to autopsy is vital for accurate PMI determination.

Purpose of the Study:

• To simulate the effect of environmental and mortuary temperatures on six forensically relevant dipteran species.
• To model insect development from the death scene through refrigeration and autopsy.
• To assess the influence of temperature variations on postmortem interval (PMI) estimations.

Main Methods:

• Collected temperature data over 16 months from external, refrigerator, and autopsy suite environments.
• Employed Monte Carlo simulation with accumulated degree-days (ADD) to model developmental variations.
• Analyzed the correlation between species' base temperatures and developmental success under different thermal conditions.

Main Results:

• A negative correlation was observed between species' base temperature and developmental likelihood.
• Insects with higher base temperatures (e.g., Chrysomya spp., Musca domestica) showed reduced development in refrigerators.
• Species with lower base temperatures (e.g., Lucilia sericata, Piophila casei) maintained development even after cooling periods.

Conclusions:

• Temperature fluctuations and refrigeration duration significantly impact insect development and PMI estimation.
• Accurate temperature recording at all stages is essential for reliable forensic entomology.
• Continued insect development despite cooling highlights the need for refined PMI methodologies in forensic investigations.