Abstract Although a corpse can harbor several species of flies, only a few have been sufficiently studied to be used as forensic indicators. Sarcophagidae are an example of how the forensic use of insects can be impaired by taxonomic and biological data limitation. This manuscript provides the first record of the Neotropical flesh fly Microcerella halli (Engel, 1931) on a human body and its use in forensics. M. halli and Sarconesia chlorogaster (Widemann, 1830) were sampled from a body located indoors at 20 °C. Only M. halli was used to estimate the mPMI (minimum post mortem interval) because it was the oldest larval stage on the corpse. Based on the development time of M. halli we estimate an mPMI of at least 10 days. In addition, we provide for the first time a case in which a flesh fly was the main source of entomological evidence in Southern Brazil. We also provide evidence that Sarcophagidae arrived before Calliphoridae in this case, an unusual successional pattern.