Forensic entomology is the study of insect biology as it relates to societal problems that come to the attention of the legal profession and that often must be resolved by legal proceedings. These problems come under the purview of medico-criminal entomology. Forensic entomology is the study of arthropods, especially insects, their identification, post-mortem intervals (PMI), crime scene details associated with crimes and other aspects of the courts and judicial system. Understanding the predictable succession patterns of Diptera and Coleoptera on decomposing remains is crucial for accurately determining the post-mortem interval in forensic investigations. Beetles and blowflies play a critical role in the decomposition process, with beetles often appearing later and blowflies swiftly colonizing remains, making both essential for accurately estimating the post-mortem interval and understanding decomposition dynamics. Insects, particularly flies, serve as crucial forensic tools, allowing for detecting drugs, poisons, and other substances long after traditional tissue samples degrade. Their ability to retain and reveal evidence, even in severely decomposed or altered remains, significantly enhances the accuracy of criminal investigations. Recent advancements in forensic entomology, such as integrating infrared spectroscopy, omics technologies, and molecular taxonomy, have significantly improved the precision and scope of forensic investigations. These tools, combined with thorough validation processes, enable forensic scientists to identify species, estimate post-mortem intervals, and interpret complex cases with greater accuracy and reliability. However, challenges such as environmental influences, insect behavior, body concealment, faunal succession limitations, and gaps in knowledge and resources present obstacles to accuracy and standardization. This review summarises key insect species involved in crime Investigation, PMI Intervals and their significance, Recent advances, Challenges and limitations so that entomotoxicologists can analyze challenging cases recovered after a long period this review also analyses the scope of entomotoxicology in the area of death investigations.