This paper presents and discusses three cases of cadavers found, unburied, in the province of Venice, Northern Italy. In each case, all insect species playing some role in carrion decay processes, both sarcophagous and their predators, found on or in the bodies, were collected and determined. In one case, many larvae of the black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae) were found and are reported, for the first time in Italy, as necrophagous. Experimental breeding of some fly species was also carried out in controlled temperature and humidity conditions. In particular, it was of interest to know how the Neotropical black soldier fly modified its life-cycle to adapt to a temperate climate. It was thus possible to establish the rate of larval growth and timing of pupation, emergence, oviposition and hatching in various external conditions. The postmortem interval (PMI) established by identifying the life-cycle stages of dipterofauna were later confirmed in all cases through police investigations and the results of forensic analyses.