Technical note: EasyPMI, online opensource application to help determine the post-mortem interval

Post-mortem interval (PMI) estimation is a critical aspect in forensic practice that is essential for legal proceedings and criminal investigations. However, it remains a challenging task subject to significant limitations in current estimation techniques, notably inter-operator variability that can affect the reliability of expert conclusions. Considering the importance and complexity of this task, as well as the lack of significant advances despite technical progress, a multimodal approach appears to be the most suitable for producing the most accurate estimation while reducing uncertainty. This article introduces an open-source application developed in Python, designed to assist forensic pathologists, medico-legal investigators, and forensic trainees in their daily PMI estimation workflow. The application implements existing body cooling equations, using numerical root-finding for the nonlinear Henssge models. By combining rectal and tympanic temperature models with established thanatological signs, this application provides a comprehensive, standardized and user-friendly tool for forensic practitioners. Built with Streamlit, this application features an intuitive browser-based interface that allows for easy data input and result visualization. The corrective factor is automatically adjusted according to body weight, reducing a common source of manual error. The application provides graphical representations of body cooling curves to aid in visualizing the results. It generates standardized PDF files for documentation and reporting, ensuring that the results are easily interpretable, reproducible and suitable for documentation in both investigative and judicial settings. The open-source architecture under the GNU GPLv3 license represents an innovation, promoting collaborative development and continuous improvement. By leveraging Python's computational capabilities and an accessible design, this application streamlines the complex process of PMI determination by combining established methods with automated calculations. Future developments will focus on integrating additional thanatological parameters and developing more sophisticated body cooling models.