Fly Artifacts (Fly Specks)
Fly specks or Fly artifacts as they are referred to, have at times been misidentified as High Velocity Impact Spatter (HVIS). I ran across some in-depth studies on the internet concerning fly specks and thought I'd do a little experiment of my own. I placed a small amount of blood on a piece of paper and then the search was on for the common house fly! It took awhile for the fly to take notice of the blood; but eventually, it did partake.
The test subject!
Notice the erratic patterns around the small pool of blood. This is caused by the fly tracking blood around as it consumed. The sperm-like pattern in the circle is from defecation.
One of the things a Bloodstain Analysts looks for in stains is directionality; however, in these stains directionality was random. Further review of the stains indicated various coloration's which could be contributed to defecation and regurgitation.
Findings: The investigator should take into consideration the presence of flies at a crime scene which involves bloodshed. Fly specks are very small and display random directionality and various coloration. The majority of stains in this experiment were 1mm or less and symmetrical with an occasional sperm-like pattern present.