What describes the term "spine" in blood spatter?

The term "spine" in blood spatter refers to elongated streaks that radiate from the center of a blood stain. This characteristic can be observed when blood droplets impact a surface, causing small projections to extend outward from the main pool of blood. These spines are significant in forensic analysis as they can help determine the direction from which the blood traveled, as well as the angle at which it struck the surface. By analyzing the spines and overall pattern of spatter, forensic experts can extract valuable information about the event that produced the bloodshed.

The other descriptions do not accurately represent the term "spine." Clusters of small blood droplets would suggest a different phenomenon, while blood type testing pertains to biological analysis rather than spatter patterns. Lastly, a circular pattern formed by blood drops may indicate a different aspect of blood-spatter analysis, typically associated with the specific impact of droplets rather than the specific elongated features that define spines.