Within the carrion insect community, carrion represents an ephemeral resource on which distinct feeding guilds arrive at particular times during decomposition. Previous successional studies have been descriptive in nature; however the mechanisms underlying the community assembly patterns have yet to be explored. Within ecology, there have been many theories proposed to explain how various communities assemble themselves, with a considerable amount of debate between the validity of neutral and non-neutral models as a driving mechanism for community assembly patterns. In order to determine the mechanism of assembly within the sarcosaprophagous guild (i.e. organisms that feed directly upon the muscle/soft tissue), two different species of blow flies (Order: Diptera, Family: Calliphoridae) were separated and placed in mesh cages to create five different treatment colonies where the sequence and species available for colonization varied. Once females were fully gravid, fetal pig carcasses (Sus scrofa) were placed within each treatment colony for 24–48 hours (depending upon treatment conditions) and colonization events were recorded. After the designated colonization period ended, piglets were removed and the larvae were allowed to feed and complete development. Upon emergence, adults were counted and an ANOVA was conducted to determine treatment effects. By varying colonization sequences and species availability, the underlying mechanisms of assembly within the blow fly family were determined; which has important implications in forensic entomology where successional patterns of insects can be used to determine the postmortem interval.