Poster Presentation Winner: Dale Rio

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Biography: Dale Rio earned a Master Degree in Crime Scene Investigations from George Washington University.


The Effect of the Substrate on Bloodstain Formation

Bloodstain pattern analysis (BPA) is an important aspect of crime scene reconstruction.  It has the potential for assisting investigators in determining important aspects of violent crimes, such as sequencing, directionality of blood droplet travel, angle of impact, and areas of impact and origin.  However, because there are many factors that can affect bloodstain pattern formation, BPA remains an inexact science.  Research exists that has qualified and quantified some of these factors, but, to date, the majority of that research has involved flat, “regular” surfaces and fails to address the possible effect irregular surfaces can have on bloodstain pattern formation.  Because the characteristics of the surface upon which a blood droplet impacts can affect the resulting bloodstain, (and because at a crime scene, target surfaces are not limited to “regular” surfaces), it is important that various surfaces, representing a wide range of characteristics, be investigated in order to assess the influence of the substrate on bloodstain pattern formation.   

In this project, high-speed photography will be utilized in order to visualize the process blood droplets undergo upon impact with different substrates.  Not only will this afford people the opportunity to see what cannot normally be observed with the naked eye, it will also demonstrate how substrate characteristics can affect the resulting stain.

Still photography will also be used to capture the stains in their final form, after they have completed all of the impact phases.  This will serve to document the end result of the process of impact.       

As it is virtually impossible to include every surface that has the potential of being impacted by blood droplets, the hope is that the results of this study will provide information that can be extrapolated and applied to other surfaces that have similar characteristics to those that were included.