Trauma

thermally induced fractures

bullseye, curved transverse and step

charred bone

carbonized, direct contact with heat and flames

heat border

off-whitish area next to charred bone protected from direct contact with heat/flames due to tissue

heat line

between unaltered and thermally altered bone

three diagnostics of thermal trauma

body position, color changes and thermally induced fractures

GSW characteristics to cranium

plug and spall, heaving concentric

GSW characteristics to long bones

x marks the spot

Class characteristics of saw

size, set, shape, power and direction

saw size

tooth or points per inch

saw sets

alternating, wavy or raker

saw shape

rip or crosscut

class characteristics of knives

blade bevel, edge bevel, serrated vs not, dimensions, orientation, depth

fractography

fracture surface morphology

bone hackle

termite path propogating away from mirror towards ridges in direction of impact

bone mirror

area of tension, smooth

arrest ridges

area of compression, ridges and valleys, perp to direction of impact

cantilever curl

final ridge on compressive side before complete failure

BFT characteristics

wide or narrow focus with blunt object, low velocity, radiating and concentric fractures

SFT characteristics

narrow focus with sharp object; punctures, gouges, cuts, stabs

material properties of bone

heterogenous, anisotropic, viscoelastic

anisotropy

will react differently based on where load is applied

heterogenous

different sizes and shapes and ratios of cortical to trabecular

stress

force applied to bone

strain

response to stress