The use of forensic tests to distinguish blowfly artifacts from human blood, semen, and saliva

This study investigated whether routinely used forensic tests can distinguish 3-day-old or 2-week-old fly artifacts, produced after feeding on human blood, semen, or saliva, from the biological fluid. Hemastix(®) , Hemident(™) , and Hemascein(™) were unable to distinguish blood from artifacts. Hemastix(®) returned false positives from negative controls. ABAcard(®) Hematrace(®) and Hexagon OBTI could distinguish blood from 3-day-old artifacts, but not 2-week-old artifacts. Phadebas(®) and SALIgAE(®) were unable to distinguish saliva from artifacts. RSID(™) -Saliva was able to distinguish saliva from 3-day-old artifacts, but not 2-week-old artifacts. Semen tests Seminal Acid Phosphatase, RSID(™) -Semen, and ABAcard(®) p30 were all able to distinguish semen from 3-day-old artifacts, but not 2-week-old artifacts. The tests investigated cannot be relied upon to distinguish artifacts from biological fluids. However, if an artifact is identified by its morphology, a positive result may indicate which biological fluid the fly consumed, and this knowledge may prove useful for investigators searching for DNA.