- An absence of blood in an otherwise continuous bloodstain or bloodstain pattern.
This void pattern was generated by placing a small funnel on top of the target. A fan was then set on medium speed and blood was dropped into the mechanism at an angle that allowed it to strike the target. The funnel was then removed.
It may be possible to determine what object was present during the bloodshed by looking at the void it created after it was removed. It may also be possible to determine the sequence of events by looking at void patterns.