| The pattern made by blood on a surface when it has been thrown off by a rapid movement. For example, when a hand or arm is bleeding profusely, it will tend to send off a shower of droplets, which will hit the walls and floor, forming a spatter pattern.
Spatter is important in the field of forensic medicine. It is possible to analyse the patterns in order to determine what caused them, how fast that something was moving, and in which direction it was moving.
Commonly, the spatter will form little exclamation marks. Taking the dot of the mark as the front, these indicate the direction that blood was thrown off. The stems of the marks indicate the speed at which they were thrown off. | 
