What Does Sharp Force Injuries Mean

edges are often free of abrasion; undermining of the edges (pocket formation) is not seen; tissue bridging is not seen

injuries caused by pointed and sharp-edged instruments

incised wounds, stab wounds, chop wounds

caused by a force that is directly roughly parallel to the surface being injured; longer on the skin surface than they are deep

wound edges may have smooth or irregular margins but abrasion of the wound margin is usually absent; do not confuse with lacerations

may have skip areas from the sharp edge having irregular contact as it is drawn over the skin

wounds caused by penetration of the body by a sharp or pointed instrument; depth of the wound is greater than its length on the skin surface

clothing may be removed from the area then stabbed in suicides

natural orientation of collagen fibers in the skin

have margins that fall closed

will gape open; measurement is not useful; wound margins should be approximated manually or using clear tape for measurement and photography

probes should be used with caution as they can cause false tracks

up/down; right/left; front/back; in reference to decedent

due to motion between the knife blade and the body during infliction of the injury; "L" "V" or "T" shaped; linear

will have 2 sharp corners

will have 1 sharp corner and 1 squared or rounded corner

a wound with two blunt corners will be made

hilt mark abrasion; contusion (impact of fist); may indicate the knife was plunged into the body for its full length; these stab wounds may be deeper than the blade is long due to skin elasticity

produce a pattern of irregular parallel linear abrasion associated with an incised or stab wound; may also produce patterned linear abrades or punctures when the knife blade is scraped across the skin or pressed against it

injuries to the extremities as the victim tries to shield themselves from the attack; consistent with homicide

palmar surface of hands from trying to grab the knife; forearms, as when blocking blows; legs, as when victim is on the ground

superficial wounds suggesting first attempts in an injury sequence; consistent with suicides

a sharp instrument with two penetrating ends (i.e. barbecue fork or scissors); measure the distance between likely pairs

caused by heavy objects with a cutting edge; wound may be deep, gaping or wedge shaped; wound may show tissue crushing and bone fractures; wound margins may be finely abraded

incised wounds can bleed profusely externally if major vessels are cut; stab wounds may have little external bleeding into the environment but marked bleeding inside the body

the evaluation of the victim's injuries does not tell the pathologist the handedness of the attacker; determination of wound track direction may correspond with certain hypotheses regarding the relative position of the knife holder and the victim

sharpness of blade or pointedness of the tip of the weapon; resistance offered by different tissues; depth and length of wound; intermediate objects such as clothing

incisions made for drainage tubes may cause contusion if the tube has been removed; occasionally a drainage tube may be inserted through a stab wound; surgeons may extend original wounds for the purpose of exploration or incorporate the original wound in a larger surgical incision such that it is no longer apparent

blood loss (exsanguination), asphyxiation due to inhalation of blood, air embolism, pneumothorax

cutting a major vein

air in pleural space with lung collapse

edges of injuries lack evidence of bleeding; joints may be disarticulated; knife marks or saw marks may be present on bone