Stereomicroscopic analysis of cut marks inflicted by a knife with blade damage.

Skeletal cut mark analysis provides relevant information on the general class characteristics of suspect knife. However, there is a lack of research on the influence of blade damage on cut mark analysis. This study aimed to thoroughly investigate the effects of damaged knife blades on cut marks' morphological and morphometrical characteristics. Fifteen undamaged, non-serrated knives were used to cut human ribs to make control cut marks. The knife blades were then damaged by a series of cuts on the bones. A comparison was made between the control cuts and 3 groups of cut marks inflicted by blades that had been damaged to different degrees. The results showed that the damaged blades created wider cut marks than undamaged one. Kerf morphology was likely to imitate the cuts made by the serrated blades such as an elliptical shape, a V-shaped cross-section and the presence of coarse striations. Wear-related features can affect cut mark analysis as the marks left behind by blades damaged to different degrees showed dissimilar dimensions and morphologies. The findings of this study can be applied to a forensic investigation when cut marks were caused by a knife with a damaged blade.

Survival of sharp force trauma in burnt bones: effects of environmental factors.

This study investigates how environmental variables, such as temperature and rainfall, affect previously induced cut marks on burnt bones. This research used non-serrated and serrated blade knives to inflict trauma on Sus scrofa ribs (n = 240). The bones were later burnt and left for 1 month in a taphonomic experimental facility. Qualitative and quantitative examinations were conducted using macroscopic and microscopic techniques to assess specific characteristics of the cut marks. Any changes to the dimension and morphology of the cut marks as well as their level of fragmentation were recorded.This study has led to three important outcomes: (1) identification of pre-existing cut marks is possible in reconstructed burnt bone fragments; (2) cut marks from different types of knife blades showed dissimilar responses to heat and the environment; and (3) specific environmental variables affect burnt bone fragmentation. These results have implications for trauma analysis on burnt remains in forensic anthropology casework.

Knife cut marks inflicted by different blade types and the changes induced by heat: a dimensional and morphological study.

Detailed information on skeletal trauma analysis of burned bone is important to ascertain the manner and cause of death in forensic casework. This research used three different knife types, one with a non-serrated blade, one a fine-serrated blade, and one a coarse-serrated blade, to inflict trauma to manually macerated Sus scrofa ribs (n = 240), and these ribs were later exposed to heat. Qualitative and quantitative analyses were conducted using macroscopic and microscopic techniques to assess specific characteristics of the cut marks. Differences in cut mark dimension and morphology of the ribs were investigated. After heat exposure, the cut marks on the rib samples remained recognisable and did not alter considerably. A level of dimensional and morphological preservation was reliant on the cutting action and the features of the knife blade as well as surrounding bone injury. The cut marks inflicted by the non-serrated blade remained recognisable despite exposure to the burning process. However, the cut marks inflicted by the coarse-serrated blade were likely to change significantly when exposed to heat. This study leads to two important results: (1) identification of pre-existing cut marks prior to heat exposure is possible in reconstructed burned bone fragments, and (2) cut marks from different types of knife blades showed dissimilar responses to heat. The outcomes obtained in this study stressed the need to adopt great care with the effects of heat on skeletal trauma analysis.

Ruptured pulmonary artery aneurysm with prior dissection and persistent ductus arteriosus: Autopsy case report.

Cardiac tamponade from ruptured intrathoracic organs can lead to sudden cardiac death. In rare circumstances, the pulmonary artery can be the source of hemopericardium. We describe a case of a 62-year-old woman with no significant past medical history, who presented with sudden unexpected death. A forensic autopsy revealed 500 ml of hemopericardium. Further dissection demonstrated a saccular aneurysm in the pulmonary artery trunk, along with the evidence of prior dissection, i.e., neointimal layer. Persistent ductus arteriosus (PDA) was also present. Pulmonary artery aneurysms (PAA) are rare and often associated with congenital heart disease (CHD). PDA is the most common CHD related to PAA. Secondary pulmonary hypertension makes the pulmonary artery vulnerable to medial degeneration and increases the risk of dissection and rupture. Careful inspection of the great vessels and congenital anomalies are essential in the forensic autopsies for sudden death investigation.

Forensic age-at-death estimation using the sternal junction in Thai adults: an autopsy study.

One of the main parameters in the analysis of skeletal remains in forensic anthropological cases is the estimation of age. This study aimed to investigate the correlation between age and the fusion status of the sternal junction. This crosssectional study was carried out on 184 sterna from 94 females and 90 males obtained from known-age cadavers in the Thai population. By direct observation, the fusion stage of the manubrio-sternal and sterno-xiphoidal junctions was studied and divided into unfused and fused joints. The results showed that a large proportion of the sterna remain unfused throughout adulthood, with fusion observed in both young and old cadavers. Insignificant differences in the rate of fusion, the sexes and ages were observed. None of the sterna under 30 years of age in females and 32 years of age in males showed fusion of the manubrio-sternal and sterno-xiphoidal junctions. Based on the variability of the sternal fusions observed in this study, we highlighted a very limited role of the sternum alone in the estimation of age in the Thai population.