Abstract: Determining the entrance and exit wounds in gunshot injuries is important for forensics. Although the
gunshot wounds have a round or oval image, there might also be atypical entrance wounds as well. When the firearm bullet hits
the cranium with an acute angle or in a tangential manner, there might occur fractures in the bevelled-out hole on the outer table;
and the defect called “keyhole lesion”, which is rare, might occur.
In this paper, the autopsy findings of a case with a gunshot wound that had atypical entrance wound in the shape of
“keyhole lesion” have been presented. The bone flaps extracted with craniectomy are stored either in the body of the patients (by
placing in the stomach or below the quadriceps) or in deep freezers. Especially in cases that have bone defects due to gunshot
wounds, the bone flap must be stored after being photographed in detail in order to prevent the findings from being lost. In
cases that have bone defects due to gunshot wounds, the distinction of the entrance and exit wounds may be performed after the
examination of the bones. Keywords: gunshot wounds, bone, entrance holes, exit holes, keyhole lesion, external lamina bevelling.