Gross and microscopic analysis of knife inflicted sharp force trauma on fresh and burnt ribs of S. scrofa

Injuries resulting from a sharp object are defined as sharp force trauma and is preserved on skeletal remains even after the carcass is burned due to the slow rate of bone decomposition. The aim of this research was to study the characteristics of incised wound in fresh and burnt ribs of domestic pig, Sus scrofa. Six racks of S. scrofa ribs were purchased and separated into vertebral and sternal end. After inflicting the injury on both part of the ribs by using smooth edge and serrated knife, the vertebral end was de-fleshed and degreased. The sternal end of the rib was burnt in an open pit fire by using wood as fuel with and without RON 95 petrol as the accelerant and analysed microscopically. V-shaped kerf, hinge fracture, mounding, linear cut, striation, flaking was among the features examined on the ribs. Striation pattern was not observed in either fresh or burnt bones. The depth of the V-shaped kerf was very distinct after burning. Linear cut and V-shaped kerf showed highest prevalence of 100% regardless of knife type and distinguishable morphologically between both knife types. Mounding and hinge fractures exhibit a prevalence of 83.33% and 66.66% respectively on fresh bone inflicted with smooth edge knife and these features showed a 66.66% of prevalence fresh bone inflicted with serrated edge knife. Post-mortem incineration affects the morphology of incised wound and the morphology of incised wound can be differentiated before and after incineration.