Page 90 - CFDI Guide

investigators, and autopsy. Judgment is deferred to the autopsy assessment as it is likely the most

accurate as to description of injuries, trajectories, and recovery of evidence from the decedent.

Most blunt force injuries can be viewed on a two-dimensional plane, the surface of the decedent or victim,
as there is often no depth or internal trajectories; sharp force injuries are different. Sharp force injuries,

particularly stab wounds, will have depth and trajectories similar to GSWs. Blunt force injuries are usually
either direct by a person, such as their fists, or an instrument – some instruments may cause either blunt

or sharp forced injuries, or only one kind. The assessment at the scene is important, as any instrument
used may be at the scene and searched for. The autopsy assessment most often includes measurements of

the injury in addition to measurements on the body to locate the injury. For sharp force injuries the
autopsy will include three-dimensional injury descriptions similar to GSW – noting measurements, depth,

and trajectory – and also if the margin edges indicate sharp or blunt (or flat) – which may be consistent
with the sharp instrument (knife blade – single sharp edge or stiletto / dagger style dual sharp edge).

Common mistakes at scene assessment, including medical treatment, is the incorrect descriptions of the

injuries. As shared in other webinars, there are three classes of sharp force injuries – stab, incised, and
chop wounds. An axe most often causes sharp force injuries with the blade, and may also cause blunt

force injuries with the butt end of the axe head (flat part opposite the blade). These sharp force injuries
may also be incorrectly described as lacerations (tearing of tissue) – when they are incised (cut tissue). The

CFDI must be accurately familiar with these, and be cognizant a report writer may not be.

Unlike GSWs, there is no additional trajectory from the body – such as an exit wound, which may assist
with determining body positions and actions. More so than GSW incidents, the events resulting in blunt or

sharp forced injuries are often more dynamic and fluid actions, with multiple events in a very short period

to an extended period of time.

Scene Description
To fully understand the dynamics of an incident involving blunt or sharp forced injuries, blood spatter

knowledge by the CFDI is important. Both types of injuries cause bloodletting, not always the first strike,
and usually from the second strike. This is not absolute, and is dependent on the instruments, injuries, and

actions. The CFDI need not know specifics of this scientific specialty, but should have a working knowledge,
as presented in this program. Knowing how the scene was assessed, and the process of interpreting blood

spatter will add a three-dimensional basis to the scene, similar to GSW trajectories. An expert will be able
to review in detail and make appropriate analysis. The CFDI should be able to determine if there are issues

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