The results showed that blow fly Calliphora vicina can alter the shape of medium-impact and pooled bloodstains by feeding. The C. vicina can consume blood and deposit insect artifacts on a range of surfaces via regurgitation and defecation. The results help familiarized law enforcement officers and crime scene investigators with the relationship between flies and bloodstains, aiding the reconstruction of crime scenes based on bloodstain pattern analyses. The successful analysis of bloodstain patterns can be a significant contribution to the investigation of death or violent crime. Some insects commonly associated with bloodstain pattern are Diptera: Calliphoridae. They are usually the first to arrive at a crime scene and can walk, eat, or lay eggs in bloodstains. Little experimental work has focused on the relationship between flies and bloodstains. Experiments were conducted to investigate the presumptive chemistry and morphology of medium-impact bloodstains on a range of surfaces for an interval of 48 hours. The investigation tested the hypothesis that the activity of C. vicina would not result in the formation of artifacts. Table, figures, and references