Entomological evidence is widely used to estimate a post-mortem interval (PMI) during death investigations. Blow flies (Diptera: Calliphoridae), typically colonize the remains within hours of death. They lay eggs on carrion, which hatch and undergo a number of predictable developmental changes. Owing to the quick colonization and reliable progression of development, investigators can use historical temperature data, stage of development, established development tables, and larval body size to backtrack from the time of collection of blow fly evidence to the time of colonization-providing a minimum PMI estimate.