View
216
Download
0
Category
Tags:
Preview:
Citation preview
Characteristics of InstrumentsCharacteristics of Instruments
SizeSize– length and widthlength and width
ShapeShape– cross-sectional outlinecross-sectional outline
round -- more fx linesround -- more fx lines
angular -- fewer fx lines, distinct edgesangular -- fewer fx lines, distinct edges
– patterned injuriespatterned injuries
WeightWeight– heavy or lightheavy or light
Effects of BFT on boneEffects of BFT on bone
Inbending at the site of forceInbending at the site of force
Outbending around the site of forceOutbending around the site of force
LeFort fracturesLeFort fractures
Ring fracturesRing fractures
Sharp Force TraumaSharp Force Trauma
Caused by an implement with an edge or Caused by an implement with an edge or pointpoint
Usually results from compression or Usually results from compression or shearing applied over a narrow focusshearing applied over a narrow focus
Complete discontinuities result from Complete discontinuities result from chopping instruments while infractions chopping instruments while infractions from cutting instruments.from cutting instruments.
Effects of Sharp InstrumentsEffects of Sharp Instruments
PuncturePuncture
IncisionIncision
Cleft/notchCleft/notch
StriationsStriations
WastageWastage
PuncturesPunctures
Caused by pointed instrument directed Caused by pointed instrument directed toward a bone surfacetoward a bone surface– Indentation at point of contact (cone-shaped)Indentation at point of contact (cone-shaped)– Depth of wound depends on instrument and Depth of wound depends on instrument and
causative forcecausative force
IncisionsIncisions
Sharp forces drawn across cortical surfaceSharp forces drawn across cortical surface– Thin lines or V-shaped indentsThin lines or V-shaped indents– Fracture lines are rareFracture lines are rare– Length, width, depth of wound depends on Length, width, depth of wound depends on
size of instrument, amt. of energy and size of instrument, amt. of energy and dimensions of bone impacteddimensions of bone impacted
CleftsClefts
Caused by vertical forces applied by Caused by vertical forces applied by heavy instruments with long, sharp edgesheavy instruments with long, sharp edges– V-shaped notchV-shaped notch– May be accompanied by radiating fracturesMay be accompanied by radiating fractures– Depth depends on force appliedDepth depends on force applied
KnivesKnives
Wound is generally small, clean and sharp Wound is generally small, clean and sharp edged - variation depends on size, type, weight edged - variation depends on size, type, weight and sharpness of the knife (e.g. paring knife v. and sharpness of the knife (e.g. paring knife v. serrated bread knife)serrated bread knife)
Knife wounds are characterized by straight lines Knife wounds are characterized by straight lines - straight lines are seldom found in nature- straight lines are seldom found in nature
Anatomy of a KnifeAnatomy of a Knife
BackBack
SpineSpine
EdgeEdge
PointPoint
RicassoRicasso
CrossguardCrossguard
GripGrip
HandleHandle
MachetesMachetes
Wound is generally Wound is generally long, deep and sharp-long, deep and sharp-edgededged
Machetes can Machetes can penetrate or penetrate or decapitatedecapitate
Other Cutting InstrumentsOther Cutting Instruments
Wound is related to Wound is related to the type of tool used the type of tool used (ice pick, hammer, (ice pick, hammer, screwdriver, pliers)screwdriver, pliers)
Tool may have Tool may have individualized individualized characteristics that characteristics that may tie it to the may tie it to the wound producedwound produced
Other tools, cont. Other tools, cont.
NEVER compromise the integrity of the NEVER compromise the integrity of the evidence by trying to fit the object into the evidence by trying to fit the object into the hole it produced. hole it produced.
One may only say that a wound is One may only say that a wound is consistent with a particular instrument consistent with a particular instrument (unless you have an individualizing (unless you have an individualizing element such as a broken tip that matches element such as a broken tip that matches the suggested tool)the suggested tool)
Wound AnalysisWound Analysis
Description of woundDescription of wound
Instrument characteristicsInstrument characteristics– typetype
cutting, stabbing, choppingcutting, stabbing, chopping
– sizesizeblade length, width, surface contour, sharpnessblade length, width, surface contour, sharpness
Direction of forceDirection of force
Number of traumatic eventsNumber of traumatic events
Recommended