What is a passive drop in blood spatter analysis?

A passive drop in blood spatter analysis refers to a blood drop created solely due to gravity. This type of drop occurs when blood falls from a certain height without any external forces acting upon it other than gravity, resulting in round droplets that maintain a consistent shape as they hit the surface below.

In passive spatter, the characteristics of the drops, such as their size and shape, can provide valuable information regarding the height from which they fell and the angle of impact. When examining passive blood droplets, forensic analysts can deduce important aspects of the crime scene, including the position of the victim or the motion of the perpetrator at the time of the bloodshed. Understanding passive blood spatter is essential for reconstructing events surrounding a crime scene, differentiating it from other types of spatter which involve additional forces at play, such as impact or propelled drops.