What shape is formed by a blood drop that has a 90-degree drop?

A blood drop that falls at a 90-degree angle to a surface will typically form a circular shape upon impact. This occurs because, at this angle, the blood drop maintains uniform surface tension, allowing it to spread out evenly in all directions before it begins to dry or form spatter patterns. The circular shape represents the initial impact and allows observers to analyze the characteristics of the drop, including its diameter, to draw conclusions about the source and velocity of the blood. As the angle of impact becomes oblique, the shape tends to become more elliptical due to the influence of gravity and motion, but at a 90-degree drop, the result remains a circle. This circular formation is essential for forensic analysts, as it provides crucial information about the dynamics of the bloodshed event.