Perimortem Trauma o Peri around surrounding o Flexible interval differences between forensic anthropology and forensic pathology o Forensic Pathology interested in whether the body is alive or not once the heart has stopped forensic pathologists declare it post mortem o Forensic Anthropology bone doesn t know that the heart has stopped the perimortem interval includes the time during which an organs properties are retained Bone retains organic properties for some time after death o Length of the Perimortem Interval depends on condition of the remains dependent on the environment o May or may not be related to the Cause of Death the Manner of Death or the Mode of Death Perimortem Trauma o Wounds will exhibit no healing o Radiating spiral hinge greenstick fractures because bone is still malleable o Sharp clean edges o Speed of impact force slow fast determination o How bone is going to racture o Energy of the object s impact has to be dispersed o Fast loading energy transmission and dispersal is fast Bone will act as a brittle material No deformation can result in radiating comminuted fracture shattering Ex Gunshot explosion react as ductile material o Slow loading energy transmission and dispersal or slow bones Can absorb energy and deform with or without fracturing Can result in warping plastic deformation Stress is applied force Strain occurs deformation Yield point bone is permanently altered warping Plastic deformation At this point the bone has not yet failed and fractured Failure point fracture occurs Ex Falls sharp force car accident blunt trauma Perimortem Trauma Fast Loaded o Ex Gunshot wound explosion shrapnel o Forensic anthro look to identify a GSW the number of events sequence and trajectory o A lot of variation in firearms weapons and ammunition o Damage will depend on the size of the projectile the construction and angle of impact o Typically bigger and faster ammo will do more damage o Caliber of weapon Don t try to determine too much variation leave that to a ballistics expert o Fracture lines from entry wounds move faster than the bullet o Fracture lines from the exit will terminate when they reach those caused by entry Helps determine sequence o The torso is more flexible than the cranium o Absorbs energy better fracture will have similar features but will not be the same o Radioplaque metal fragments visible in xrays with GSW o GSW Projectile impacts bone entry Creates larger defect at the exit surface Result is beveling May or may not have exit wound Exit will be larger and more irregular than entry GSW shape Depends on the angle of impact Circular perpendicular impact Oval tumbling or angled impact Keyhole tangential impact entry wound entry surface and exit surface exit wound entry surface and exit surface GSW Fracture Plug and Spall o entry exit o Plug entry o Spall chips along exit surface Radiating fractures o Fracture that moves outwards from the point of impact follows path of least resistance Concentric heaving o external beveling o Formed between radiating fractures Trajectory Sequence o Look for the bevel o External bevel on entry o In cases of close range discharge reverse bevel confusing term professor doesn t like this term Say Circumfirential Delamination Better term Not a bevel not the same process Sequence look for terminatory fractures Post Cranial Damage More comminution depends May require reconstruction May may not show beveling Lead wipe will still be visible in xray Perimortem Trauma Slow Loaded o Ex Blunt force car accident falls impact o Damage will depend on amount of energy transmitted to bone the higher the energy the more damage o Bone is stronger in the direction it is usually loaded o Bone is weaker under tension will fracture first o Fractures propagate along the path of least resistance o Puppe s Law of Sequence Fractures from a second impact site will terminate in fractures from the first impact previous site o An infinite number of objects can be used to cause Blunt Force Trauma o Implement and force determines the shape and extent of the injury o Linking the specific weapon to the trauma only if there is trace evidence available hair blood fibers from the victim s clothes o Patterned injuries may be able to suggest a class of object o The age of the individual can also affect the damage Young higher resistance to fractures due to unfused epiphyses more cartilage and collagen content Older more likely to fracture due to brittleness loss of organic properties ossification of cartilage o General Characteristics of Blunt Force Trauma Warping depressed crushed areas linear fractures hinging Forensic Anthropologists look at number of impacts sequence and direction if possible o Cranial Blunt Force Trauma fracture appears first in areas of tension May or may not show external beveling o LeFort Fractures type typicality Found in blunt force trauma typically hits to the midface LeFort 1 separates maxilla LeFort 2 separates midface LeFort 3 separates the facial skeleton o Multiple episodes of blunt force trauma Extensive damage Realize reconstruction bones are warped Impact marks o Butterfly Fracture Fracture started at the base may occur in GSW typically is of BFT o Simple Linear Fracture Ex Car pedestrian accident Fracture symmetry Crushing hinging o Sharp Force still slow loaded angle of impact Force Trauma traits axes etc Typically think cutmarks from a knife Bt also saws and other implements with a sharp edge Amount of damage depends on instrument force applied and Wound can begin as Sharp Force Trauma and end as Blunt Instruments with squared edges will produce trauma with BFT Ex Bush hogs augurs tree chippers boat propellers swords Amount type of damage Instrument short light vs long heavy weapons Force highly variable Direction Perpendicular with the grain causes slit in bone Perpendicular against the grain cut into the bone Angled against grain hinging slicing Other terminology wall floors of a cut mark Kerf Wastage chattering displaced bone fragments around the impact site Types of Wounds Puncture gouge o Indentation at the point of contact the size and depth is variable force is perpendicular to bone surface Incisions cutmarks o Linear shape size depth variable sharp edge applied across bone surface slice Cleft chop wound o Perpendicular force wound is large and deep may have wastage comminuted fracture Other o Straight edge flat plane o No wastage o Not a break animal damage Punctures and incisions short light objects