This document reports on a project aimed at creating fluvial transport models to predict where to search for human bodies within the Sacramento River, in California.
This report addresses the difficulties faced by law enforcement and search and rescue teams in identifying search parameters for deceased persons in bodies of water, especially over long postmortem intervals such as multiple days or weeks. The research project documented here created fluvial transport models to predict where to search for human bodies within the Sacramento River. The report describes the following the research design and data collection on historical cases of river victims from law enforcement agencies, including dates, times, and locations of entry and exit from the river; methodology, which included “sinker” and “floater” water rescue mannequins used to simulate dead bodies in submerged and floating stages, GPS and salmon tracker devices for evaluating transport rates of the mannequins, and an adaptation of the Army Corps of Engineers’ Hydraulic Engineering Center River Analysis System (HEC-RAS), to predict transport rates under different flow rate conditions. The results of this study have been disseminated to the forensic science and forensic anthropology communities through presentations at annual meetings; to the California Department of Justice and California Peace Officers Standards and Training courses, and more; and other relevant journal publications. The authors disclose the limitations of the study, snagging issues involving natural and constructed hazards, the HEC-RAS model required significant modifications to create reasonably accurate simulations, and case information was often old and incomplete; the authors note their plan to provide a data collection sheet of recent cases’ GPS coordinates and files to the appropriate agencies, to facilitate the use of the Sac River Search application. Appendices with maps, images, and charts are included.