The utility of blow fly (Diptera: Calliphoridae) evidence from burned human remains

• Published in: Forensic science international Vol. 356; p. 111962
• Main Authors: Owings, Charity G., McKee-Zech, Hayden S., Orebaugh, Jack A., Devlin, Joanne L., Vidoli, Giovanna M.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.03.2024; Elsevier Limited
• Subjects: Anthropology; Arthropods; Blow fly; Burn; Burning; Colonization; Criminal investigations; Decomposition; Entomology; Evidence; Fire; Flies; Forensic anthropology; Forensic entomology; Fractures; Human remains; Insects; Murders & murder attempts; Placement; Prescribed fire; Research facilities; Species composition; Summer; Time of colonization; United States > US; Blow fly; Burn; Decomposition; Forensic entomology; Time of colonization; Fire
• ISSN: 0379-0738; 1872-6283
• DOI: 10.1016/j.forsciint.2024.111962

Burning of human remains is a common method to conceal or destroy evidence associated with homicides and illegal activities. However, data regarding blow fly colonization of burned remains are scarce, with all previously published empirical studies focusing only on non-human animals. It is critically important to obtain basic data on blow fly colonization patterns of burned human remains as such evidence may represent the only feasible method for PMI estimation in cases of burning. In this study, we thermally altered six human donors to a Crow-Glassman Scale Level 3 (CGS-3) and placed them at the Anthropology Research Facility at the University of Tennessee in Summer 2021, Spring 2022, and Summer 2022. Six unburned human donors were used as controls. Observations for insect activity began within 24 h of placement and continued twice weekly through decomposition. Age estimations were performed with immature blow flies to estimate the time of colonization (TOC), and accuracy was assessed against the time of placement for each donor. All burned donors examined in this study were colonized by blow flies. No significant difference in species composition was determined between treatments, though TOC estimations from burned donors were slightly (but significantly) less accurate than TOC estimations from unburned donors (80% vs. 83% accuracy; χ2 = 0.041, df = 1, P = 0.840). These results indicate that blow flies can successfully colonize human remains burned to CGS-3 and that accurate TOC estimations can still be generated from larval specimens. Though several limitations to this study exist (e.g., inconsistent donor BMI, lack of donor temperature data), our results underscore the utility of entomological evidence in cases of burned human remains. •Little is known about the impacts of advanced burning of human remains on postmortem arthropod activity.•We thermally altered intact, donated human bodies and observed postmortem blow fly activity.•Five species of blow flies successfully colonized burned human remains.•Most time of colonization estimations were accurate for burned remains.•Thermal imaging can be a useful tool for detecting blow fly larvae on burned remains.