Burned bones provide compelling forensic evidence.

Burnt bone pieces can provide crucial information in forensic casework, which is critical to determining the victim’s identification. The physical and chemical properties of burnt bones are significantly altered, which could pose a problem for anthropological and DNA testing. Bone identification becomes more difficult as the exposure temperature rises.

Abstract:

In this section, we’ll examine the many alterations that bone undergoes due to being heated to such high temperatures. Other cutting-edge tools for anthropological investigation include micro-computing tomography imaging for identifying burnt bones. Bone modifications after burning and their impact on the interpretation of test results necessitate a thorough investigation.

Introduction:

Charred bone identification is an issue that frequently arises during investigations. Bone’s chemical and physical properties are drastically altered in a fire, making forensic identification more difficult.

Identification of burnt bones:

Research on burnt bone identification has been published in various book chapters and reviews. Other topics covered include evidence recovery, the significance of artificial materials connected with burnt bones, and strategies for gathering burnt bone specimens when mixed with other types of evidence.

Traditional anthropology has several challenges.

The chemical composition of burnt bones presents a unique set of obstacles for typical anthropological and DNA testing. Additionally, micro-CT imaging will be introduced to aid in identifying charred bone as part of this update.

Burned bones provide compelling forensic evidence:

Car accidents, mass catastrophes, and residential fires all contribute to collecting burnt bones in forensic laboratories. Intentional incineration and destruction of a victim’s body by the perpetrator to impede an investigation are not unusual homicides. This task is made more difficult by the heat-induced disintegration and subsequent artificial crushing of burned bones. DNA analysis of burnt bones, on the other hand, is extremely difficult.

The hue of charred bones:

In comparison to the unburned bone, burnt bone seems to have a distinct color. Several tests have developed an indicator for determining bone sample exposure temperature by examining the relationship between the surface color and the burning temperature. There is also a correlation between burn length and the severity of bone pigmentation alterations. In anaerobic settings, the coloration process is retarded.

Pre-combustion stages:

During the initial stages of combustion, the bones are kept anaerobic by the soft tissues of the corpse. Charred bones can vary in severity even within the same person, depending on the amount of soft tissue in the body and the heat dispersion during the burning process.

Colorimetric approaches are used to identify charred bones:

In the past, these changes were depicted in photos and color charts. They were using the colorimetric approach of CIELAB (the CIE-recognized LAB-based color model). A study by Fredericks et al. found that burnt bone color was correlated with successful DNA testing. This technique is predicted to be used in the future because of its high level of objectivity and reproducibility.

Loss of weight due to a reduction in bone mass:

Bone mass reduces during burning because of water evaporation and organic molecules that produce carbon dioxide. Following the cremation process, the bones of female and male corpses are left behind. When intentionally burned bones were weighed, researchers found that the weight loss occurred after being heated to a certain temperature.

Ortner and Turner-Walker:

Although the weight loss increases and eventually reaches 60% of its original weight at 400°C, it is still a considerable increase. According to Ortner and Turner-Walker, bone mineral makes up 62% of compact bone, with 14% water and 24% organic matrix. It means that burning would not liberate any mineral from the bone. It means that burned bone sheds water and a considerable percentage of its organic matrix at 400°C, and at 700°C, it is entirely devoid of the organic matrix.

Burnt bone temperatures:

There was a considerable decline in collagen, which became less noticeable at 700°C when the collagen was eliminated. In line with the above description, burned bones have a diminished biological matrix. DNA testing on burned bones needs to account for this early loss of the organic matrix, as the bone’s DNA is organic.

Charred bones shrink and deform due to inflammation:

Bone loss occurs as a result of the burning process. Volume analysis in its fractured and fragmented condition is problematic due to the difficulties in measuring volume. A quantitative evaluation of charred bone volume loss has not been established.

Dense bone was minced and burned:

Micro-CT analysis accurately reduced the volume of cubed and burnt dense bone. Compared to weight changes previously documented, temperatures surpassing 1,100°C results in a considerable drop in bone volume. Until temperatures increase above 600°C, the volume remains unchanged.

Results:

The experimental investigations on bone coloring are all slightly different because of the variances in sample size, type of furnaces, supply of oxygen, and burning time. The relationship between bone color and temperature isn’t a straight line. Color changes from yellow to brown to dark brown to black to ashy grey and eventually white with higher temps.

Result of the combustion and pyrolysis:

Combustion and breakdown of chemical substances in the burning process affect bones chemically as well. A rise in temperature means an increase in alterations. Forensic identification methods are impacted by DNA deterioration. The specimen’s temperature and other environmental factors should investigate further. Using this data, investigators can better decipher test findings from burned bones.

Summary of findings:

This study reviewed several papers on the identification of burnt bones. There have been numerous studies on this topic over the years, each representing a distinct point of view. For all that we know about burned bone at this point, researchers are continuously working on new ways to identify it.

Read also: A snippet of Roberge’s History.

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