Bloodstain pattern analysis aims to test hypotheses that can explain some of the facts of a possible criminal offense. This takes place using the information obtained from the investigation to determine the area of origin, shape and volume of blood.
Basics of bloodstain pattern analysis
- Blood behaves according to the laws of physics. If in liquid phase and in motion, the properties of blood are described according to the laws of science, in particular those of ballistics (the science of projectiles in motion);
- The rate at which the blood moves from the start, is directly related to the size of a blood droplet. For example; greater force is required to produce a smaller drop;
- Based on the shape of the bloodstain that occurs after it impacts a surface, one can determine the direction in which the blood drop was moving. A bloodstain points towards the direction in which the blood was moving;
- Bloodstain patterns are predictable and reproducible.
The term bloodstain is used when one cannot determine the mechanism that caused the bloodstain pattern.
Blood spatters are derived from blood on which force is applied. Blood spatter patterns can be classified into the following categories:
- Blood drops from arterial bleeding;
- Cast off drops of blood from a swinging object;
- Drops from an impact in liquid blood for example from beating. As the force of impact increases, smaller blood droplets form;
- Satellite Stains: droplets of blood scattered around a drop or a pool of blood;
- Drops that arise because blood has been expelled out of the airways due to coughing/breathing.
Blood spatters caused by an impact in liquid blood
When force is applied to a source of liquid blood, an impact pattern will occur near this event. The resulting blood droplets travel through the air like small spheres. If a drop of blood impacts a surface at an angle it produces an elliptical shape.
IFS experts have investigated hundreds of cases where bloodstains tell the story. Our knowledge is extensive and we perform our own tests to reproduce events.
Hourly fee for analysis $200