Blood droplet dynamics--I.

The interpretation of bloodstain patterns at crime scenes has received increased attention in recent years. Important to an understanding of this is knowledge of the fundamentals of blood droplet formation and impact dynamics. A review of the literature reveals that a considerable amount of work has been done with aqueous drop dynamics. Workers in the forensic science area seem to have been unaware of this. In addition, some of the most important and comprehensive early work with blood droplet dynamics seems to have been forgotten. It is not cited in more recent publications dealing with bloodstain pattern interpretation. This literature is reviewed and discussed as well. The present study presents results of experiments with blood droplet dynamics and high-speed photographs of blood droplet impacts on stationary target surfaces. Some longstanding misconceptions of importance to forensic scientists engaged in crime scene reconstruction are discussed.