What It Provides ^

Bloodstain pattern analysis can provide information about the type of weapon or object used, the impact velocity and the number of impacts, and the number of people present at the scene. A void in an otherwise continuous bloodstain pattern usually indicates that an object or person was interposed between the source and the target surface. It can also reveal how the perpetrator and the victims moved before and after the crime, whether the body was moved, when the crime occurred, and whether death was instantaneous or occurred later.

As is readily understood, a person who died, for example, from a single gunshot wound to the head will not leave the same bloodstain pattern as someone who died from blows with a club.

For this purpose, analysts draw conclusions after examining and comparing all the findings. The objective is for the conclusion to be sufficiently objective and reliable that any other analyst who repeats the analysis will reach the same conclusions.

Literature-Based Approach ^

Typical Bloodstain Shapes at Various Angles of Impact.

Blood-Drop Trajectory Diagram. Source: yoair.com/forensic-anthropology.

Calculation of Bloodstain Angles of Impact. Source: OffGridWeb.com.

Analysis of Real Cases ^

Bloodstain Pattern Resulting from the Movement of an Injured Person.

A Blood Pool with Spatter Stains, Indicative of the Body's Direction During the Fall.