Artifacts Caused by Leaf-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae): Postmortem Bite Injuries and the Tearing of Clothes.

Ants are one of the first insects to find an exposed cadaver and can be present during all stages of decomposition. Although these organisms are not commonly used in postmortem interval estimates, they are to be taken into account on criminal investigations involving human corpses, since they can leave bite marks that can be mistaken for antemortem or perimortem injuries, which could be misleading when ascertaining the occurrence of abuse or physical altercation during a crime. A few studies report the action of ants on human cadavers and even though leaf-cutting ants of the genus Atta are frequently encountered in succession studies that use animal carcasses, there are no records of these fungus-growing species on human corpses. Atta is a genus restricted to the New World, ranging from northern Argentina to southern United States and acts as one of the most conspicuous neotropical herbivores. In this study, we report three cases of violent death that illustrate the impact of ants, especially those of the genus Atta, in a forensic setting. We compare the patterns displayed by postmortem bite injuries caused by leaf-cutter ants and other common species with less robust mandibles. We also present the capability of Atta ants to create artifacts by cutting victim's clothes in a crime scene, contributing to the knowledge of ant-mediated confounding factors in crime scene investigation.

Death Scene Investigation and Autopsy Practices in Sudden Unexpected Infant Deaths.

OBJECTIVE: To describe and compare sudden unexpected infant death (SUID) investigations among states participating in the SUID Case Registry from 2010 through 2012. STUDY DESIGN: We analyzed observational data from 770 SUID cases identified and entered into the National Child Death Review Case Reporting System. We examined data on autopsy and death scene investigation (DSI) components, including key information about the infant sleep environment. We calculated the percentage of components that were complete, incomplete, and missing/unknown. RESULTS: Most cases (98%) had a DSI. The DSI components most frequently reported as done were the narrative description of the circumstances (90%; range, 85%-99%), and witness interviews (88%, range, 85%-98%). Critical information about 10 infant sleep environment components was available for 85% of cases for all states combined. All 770 cases had an autopsy performed. The autopsy components most frequently reported as done were histology, microbiology, and other pathology (98%; range, 94%-100%) and toxicology (97%; range, 94%-100%). CONCLUSIONS: This study serves as a baseline to understand the scope of infant death investigations in selected states. Standardized and comprehensive DSI and autopsy practices across jurisdictions and states may increase knowledge about SUID etiology and also lead to an improved understanding of the cause-specific SUID risk and protective factors. Additionally, these results demonstrate practices in the field showing what is feasible in these select states. We encourage pediatricians, forensic pathologists, and other medicolegal experts to use these findings to inform system changes and improvements in DSI and autopsy practices and SUID prevention efforts.