What creates a wipe pattern in blood spatter analysis?

A wipe pattern in blood spatter analysis is formed when an object moves through or across existing blood on a surface. This movement essentially disrupts or alters the blood pattern as the object contacts the bloodied surface. The resulting pattern can indicate the direction and speed of the object, providing crucial information about the events that took place during a violent incident.

The characteristics of a wipe pattern include the smearing or smudging of blood that often retains the shape of the object that created it. This can help investigators determine not only the location of the blood but also the potential path taken by the object, adding context to the scene of the incident.

Other patterns associated with blood spatter, such as those caused by air pressure or from drips, do not create wipe patterns. For instance, the impact of blood droplets does not involve objects moving through the blood, nor does a slow drip from a height alter existing blood patterns in a way that would match the definition of a wipe. The understanding of wipe patterns, therefore, is vital for interpretation in forensic analysis.