Recognition and limitations of postmortem abrasion assessment
THE CONTEXT
The timing of an abrasion relative to death can be difficult to establish, and drying or immersion can alter its visibility and appearance.
Limits of differentiation
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Abrasions produced slightly before or after death cannot be differentiated even microscopically.
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Differentiation is difficult in superficial lesions and in advanced decomposition.
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Drying makes abrasions dark brown or even black. In bodies recovered from water, abrasions may initially be inconspicuous but become easily visible after the skin dries.
Postmortem production and distribution
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Dragging a body from a crime scene can produce postmortem abrasions. Their distribution depends on the body's position during dragging.
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Typical sites include the forehead, prominent facial points, anterior trunk, backs of the hands and fronts of the lower legs.
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Facial injuries may ooze blood and mimic antemortem wounds.
Appearance and circumstances
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After death, abraded epidermis becomes stiff, leathery, parchment-like, brown and more prominent; it may be mistaken for a burn.
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This change is classically seen in ligature marks of hanging and strangulation.
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Abrasions are usually associated with accidents and assaults; suicidal abrasions are rare.