Bloodstain Pattern Analysis - Point and Area of Convergence

Point and Area of Convergence

To determine the point/area of convergence an analyst has to determine the path the blood droplets travelled. The tangential flight path of individual droplets can be determined by using the angle of impact and the offset angle of the resulting bloodstain. “Stringing” stains is a method of visualizing this. For the purpose of the point of convergence, only the top view of the flight paths is required. Note that this is a two-dimensional (2D) and not a three-dimensional (3D) intersection.

• The point of convergence is the intersection of two bloodstain paths, where the stains come from opposite sides of the impact pattern. (see figure 3)

• The area of convergence is the box formed by the intersection of several stains from opposite sides of the impact pattern. (see figure 4)

In the past, some analysts have drawn lines along the major axes of the stains and brought them to an area of convergence on the wall. Instead of using a top-down view, they used a front view. This provides a false point/area of convergence.