Area of Convergence
Definition
The 2-D point on a surface where the projected trajectories of multiple impact stains intersect. It's the floor-projection of the impact source.
- Dimensionality
- 2-D point on a surface
- Derived from
- Projected trajectories of impact stains
- Relationship to area of origin
- Floor-plane projection of it
- Discipline
- Bloodstain pattern analysis
Common questions
How is the area of convergence determined in practice?+
Analysts draw straight lines back through the long axis of multiple individual bloodstains on a two-dimensional surface such as a wall or floor; the point where enough of these lines intersect is taken as the area of convergence for that pattern.
Why isn't the area of convergence enough to locate where the blood-shedding event happened?+
It only shows a two-dimensional intersection point on one surface, with no information about height above that surface, so the analyst still needs the impact angle of each stain to calculate the three-dimensional area of origin.
Related terms
- Area of Origin
- The 3-D point in space where the blood-shedding event occurred, derived from the area of convergence plus the angle of impact for...
- Cast-Off
- Blood thrown off a swung object (a hammer, a knife, a bat). The trail records the arc of the swing and often...
- Non-Newtonian Fluid
- A fluid whose viscosity changes with the shear rate. Blood thins under fast shear (a fast swing of a weapon) and thickens...
- Parent Stain
- The primary drop that produces a drip pattern. The smaller surrounding spatters are the satellite spatter; together they tell you about drop...
- Surface Tension
- The cohesive force at a liquid's surface that lets a drop hold a spherical shape in flight. Whole blood sits around 58...