Previous carrion studies have described the disruptive behaviors of the invasive hairy maggot blow fly, Chrysomya rufifacies (Macquart), towards predatory necrophilous beetles such as the hairy rove beetle, Creophilus maxillosus (L.). Such studies stated that C. rufifacies larvae repelled native blow fly larvae, predaceous beetles, and ants away from vertebrate carcasses. Our main research objective was to test the predatory behaviors and feeding patterns of C. maxillosus adults towards two blow fly species, C. rufifacies (invasive species) and the secondary screwworm, Cochliomyia macellaria (F.) (native species), in a laboratory setting. Starved C. maxillosus were placed into individual 0.47-L clear plastic cups, provided one third instar blow fly, and observed continuously for two hours. Predatory and feeding responses were recorded as: 1) alive, not eaten; 2) killed, not eaten; 3) killed, consumed partially; or 4) killed, consumed entirely. In total, 342 observations were performed, including 191 and 151 replicates of one beetle and one larva of C. rufifacies or C. macellaria, respectively. Chi-square test of independence was highly significant (P < 0.0001) for both analyses, and the likelihood of C. maxillosus ‘killing and not eating’ a fly larva versus ‘killing and eating’ the prey was highly significant per fly species (P < 0.0001). Additional observations on predatory and defensive behaviors, handling and feeding patterns, and beetle fecundity are discussed.