Insects attracted to cadavers can be used to estimate postmortem interval (PMI). In this study, inmature stages and adults of Dermestes maculatus and Chrysomya albiceps were collected in association with a human cadaver in a closed aquatic environment in Caquetá, Colombia, and analyzed to determine the PMI. We also conducted an experiment with a pig carcass to estimate the emersion time, which began three days after carcass submersion. The minimum PMI was 481.5 hours. Time of death, time of emersion and period of insect activity matched the actions of the murder suspects, who confessed to murdering the victim 25 days prior to the discovery of the body.