The kind of insects we find on/in a cadaver can give useful information of how long it was on the ground. Each stage of decomposition gives a certain profile of such organisms feeding/breeding on/in a dead body
Yes, as Charles and Jean-Pierre mention, Insect analysis has been used in legal investigations for decades in a practice now known as forensic entomology. Increased interest in this field since the late 20th century has resulted in more frequent use of forensic entomology in investigations and the development of research on necrophagous species.
Scientists have increased interest in studying the succession of insects in the detection of bodies and life cycles and what the role of this succession in resolving many criminal cases. "One of the first to report on the use of insects in legal or legal medicine is the French physician Bergeret d'Arbois (Bergeret 1855), who first used the concept of insect succession in determining the post-mortem period of human remains."
Agreed with Dr Vincent and Luis Miguel Constantino
Also, Entomology science by insect classification can help in reveal many crimes and murder. Forensic Entomology is kingdom of criminology and Forensic medicine that uses of insects for PMI=Post Mortem Interval, Displacement of the corpse, death due to toxication and etc.
This has been used in forensic analysis in the USA. Analysis of maggots found on dead bodies in the crime scene can help determine the time of death. In addition, analysis of the bugs can result in assessing if the person died of positioning.