Bloodstain Pattern Analysis

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Pages: 8

Bloodstain pattern analysis is defined as the interpretation of bloodstains at a crime scene in order to recreate the actions that caused the bloodshed (Akin, 2005). This paper will go into what the different kinds of bloodstain patterns are and how their interpretations can aid a crime scene investigation. There are different velocities that blood can be spattered at and from those spatters the central point of convergence can be found to determine where the crime was committed. There are three ways to classify the speed that caused bloodstains. The three velocities of blood spatter are high, medium, and low velocity. The low velocity spatter is only formed by external forces created by objects that are moving less than five feet per second. …show more content…
These stains are formed by blunt or sharp trauma that includes but is not limited to knives, hatchets, clubs, and fists. Arterial spurts are also in the medium velocity category of blood spatter. The stains formed by medium velocity spatters generally measure between one and three millimeters. It will take more than one blow to create medium velocity spatter since the victim has to be struck at least once to break the skin and start bleeding. By analyzing the medium velocity spatter the minimum amount of times that the victim was hit can be determined, but there’s no way to know the maximum amount of times they could have been hit (Akin, …show more content…
3D documentation starts with taking two images of the bloodstains at different angles with a calibrated camera. A machine called a tachymeter can then measure the distance between points of interest in the entire crime scene. These points of interest can include things as large and broad as the size and shape of the crime scene to things as small as the size of the bloodstains and the distance between the stains. After the data is collected is is input to a program that outputs an accurately scaled 3D model of the crime scene and the bloodstain pattern. From all of the data, the program can also make trajectories of the bloodstains and show the most likely places that the center of origin is located in the 3D rendered model of the crime scene (Buck, et al.,