Internal Assessment Blood Splatter Patterns
Introduction:
Bloodstain spatter pattern analysis is one of several specialities in forensic science. The analysis of the blood droplets upon contact with a surface is used to create a three dimensional space symbolizing the area of convergence of all the stains, this method is used to find the source of the blood. The source of the blood helps forensic analysts to understand the crime scene better and thus have an understanding of where the incident took place. A blood droplet in free fall has the form of an oscillating sphere. This spherical shape of blood in flight is important for the calculation of the angle of impact (incidence) of blood spatter when it hits a surface. That angle will be used to determine the point from which the blood originated which is called the Point of Origin or more appropriately the Area of Origin. A single spatter of blood is not enough to determine the Area of Origin at a crime scene. The determination of the angles of impact and placement of the Area of Origin should be based on the consideration of a number of stains and preferably stains from opposite sides of the pattern to create the means to triangulate.
Pig blood was used in the experiment. The pig blood was extracted from a pig heart that was sold at a butchery. The process of acquiring the blood was very tedious, finding real blood proved to be a very hard thing to do in Kraków. However after searching for a period of 3 weeks I finally found real pig blood in a fresh meat distributor.
Experiment:
The experiment took place in a closed system to get the best results possible for the investigation. The blood was projected from a single point in the room where the experiment was done and, for the purpose of this experiment, projected using a cleaving motion to replicate the action of swinging a knife to replicate the bloodstains found near actual murder scenes.
The digital scan of the wall, shown in figure 1, shows the blood spatter
Bloodstain spatter pattern analysis is one of several specialities in forensic science. The analysis of the blood droplets upon contact with a surface is used to create a three dimensional space symbolizing the area of convergence of all the stains, this method is used to find the source of the blood. The source of the blood helps forensic analysts to understand the crime scene better and thus have an understanding of where the incident took place. A blood droplet in free fall has the form of an oscillating sphere. This spherical shape of blood in flight is important for the calculation of the angle of impact (incidence) of blood spatter when it hits a surface. That angle will be used to determine the point from which the blood originated which is called the Point of Origin or more appropriately the Area of Origin. A single spatter of blood is not enough to determine the Area of Origin at a crime scene. The determination of the angles of impact and placement of the Area of Origin should be based on the consideration of a number of stains and preferably stains from opposite sides of the pattern to create the means to triangulate.
Pig blood was used in the experiment. The pig blood was extracted from a pig heart that was sold at a butchery. The process of acquiring the blood was very tedious, finding real blood proved to be a very hard thing to do in Kraków. However after searching for a period of 3 weeks I finally found real pig blood in a fresh meat distributor.
Experiment:
The experiment took place in a closed system to get the best results possible for the investigation. The blood was projected from a single point in the room where the experiment was done and, for the purpose of this experiment, projected using a cleaving motion to replicate the action of swinging a knife to replicate the bloodstains found near actual murder scenes.
The digital scan of the wall, shown in figure 1, shows the blood spatter