One analytical technique I often use may have an application in this case. This can only be performed if there is sufficient data (I do not know about the actual forensic data in this case.) What you see here is only an example; it is not one of the crime scenes nor does it show data from an actual victim.

The Wound

 

In some cases, a good autopsy can describe the bullet's path through the body sufficiently to establish a wound path. When the entry and exit wounds (if there is an exit) are located and measured, all this data may allow a determination of the horizontal and vertical angle through the body.