The use of insects to elucidate time of death and suspects association to the scene crime: three cases reported in southeastern Brazil

One of the mainly applications of Forensic Entomology is the use of developmental and ecological data of necrophagous insects to estimate the post-mortem interval (PMI) in criminal investigations. The knowledge about the time of death is important because it can allow the police officers to include or exclude probable suspects to a homicide case. In Brazil, entomological evidence is still neglected, so cases involving the use of insects to estimate the PMI are rare. In three occurrences of encounter of cadaver analyzed by a unit of the Institute of Criminalistic (IC), specimens of dipterans that were colonizing the corpses were collected using forceps, put in containers and taken to the IC to proceed the identification of the material, aiming to aid in the elucidation of the cause and manner of death in the municipality of Franca, State of São Paulo, Brazil. The bodies of the victims (two men and one woman) were in decay process of decomposition. The blowflies larvae of corpses 1 and 3 were identified as belonging to the species Chrysomya albiceps while the larvae of corpse 2 were identified as being Hemilucilia semidiaphana. The estimative of PMI was done by considering the environment temperature data (obtained from the nearest weather station of the area where the corpses were found), laboratorial data on developmental rate of the mentioned species, and in comparison with field research conducted in the same region using domestic pig as animal model. Based on the age and behavior of the larvae, it was possible conclude that the people who were last seen with the victims in both case 1 and 2 had involvement with the crime and with regard to case 3 this was a natural death and not murder.