Application of aquatic decomposition scores for the determination of the Post Mortem Submersion Interval on human bodies recovered from the Northern Adriatic Sea

Forensic study of the mechanical properties of prosthetic materials: Submersion in mangrove environment - A pilot study

INTRODUCTION

It is crucial for dental surgeons to use the mechanical properties of dental prosthetic materials to correlate the submersion time in a mangrove environment.

OBJECTIVE

This study aimed to submerge dental prosthetic materials, such as acrylic resin and zirconia, contained within acrylic resin disks in a mangrove environment, and analyze the alterations in mechanical parameters, such as surface roughness and microhardness, to estimate submergence time in similar forensic situations.

MATERIALS AND METHODS

A total of 6 specimens was embedded in acrylic resin disks numbered from 1 to 6. The materials were polished for initial parameter readings a day before submersion, and new readings were obtained 1after submersion. All specimens were subjected to surface roughness analysis, in addition to Knoop microhardness analysis for acrylic resin and Vickers microhardness analysis for zirconia. After the experiment, the data were computed for statistical comparation of the materials properties different parameters.

RESULTS

There was a significant increase in surface roughness and Knoop microhardness was reduced in the Acrylic Resin samples (p< 0.05); however, no statistically significant differences were observed in the roughness or Vickers microhardness values of the zirconia samples.

CONCLUSION

Zirconia prosthetics were more resistant to degradation when submerged in a mangrove environment compared to acrylic resin ones; however, owing to the obstacles inherent in this study, we suggest further research on the properties of prosthetic materials submerged in mangroves or other environments, which could bolster the work of dental professionals in forensic medical institutes.

Water-related fatalities: An examination of body displacement and recovery patterns in British Columbia, Canada

Early recovery of human bodies from the water requires an understanding of how a body acts in the water. However, there is currently a lack of baseline data surrounding body movement in British Columbian (B.C.) waters. This study aims to assist Canadian response agencies with understanding and predicting body movement in outdoor waterbodies in B.C. One hundred and eighty-six water-related fatalities in B.C. waters, including lakes, rivers, and the coastal Pacific Ocean, were examined to determine the recovery times and displacement patterns of submerged decedents. Cases between 2010 and 2021 were extracted from the Police Records Information Management Environment (PRIME-BC) for analysis. Most deaths were unintentional, followed by suicide and homicide, and most often occurred in rivers, followed by lakes and the ocean. Regardless of waterbody, the first day was the most successful recovery period, with decedents most often recovered close to the incident location. Nearly 16% of individuals in this study were not recovered. Recovery success was greatest in lakes, followed by rivers and the ocean. Body displacement was the least in lakes, while rivers resulted in the furthest and most variable displacement. Low recovery success in the ocean is likely due to decedents being quickly displaced out of the search area, never to be found. The results of this study suggest that knowledge of body movement in outdoor aquatic environments remains incomplete. Further empirical research based on known data is necessary to continue improving prediction of body movement and increase early recovery success.

[Determination of the corpse's stay in the water duration according to maceration degree of its skin]

A serious problem during the postmortem examination of a corpse extracted from the water can be a significant determination of its stay in the water duration. First of all, the signs indicating the presence of a corpse in the water include maceration, according to the severity of which forensic experts often determine how long the corpse stayed in the water. The aim of the study is to summarize the available literature data and propose ways to objectify the determination of a corpse's stay in water duration by the severity of skin maceration. In this article, based on the analysis of literature, the process of skin maceration is described, as well as the timing and speed of its development according to various authors. The presence of quite a large number of external and internal factors affecting the process of skin maceration and the subjectivity of its severity assessment is indicated. This article provides examples of the biophysical methods usage for the study of biological objects in forensic medical examination, allowing to objectively record changes in the researcher's parameter of interest. The use of skin impedancemetry to objectify the severity of skin maceration.

Taphonomic study on drowned victims in a non-sequestered aquatic environment in the Mediterranean Sea

Human decomposition in sea water poses several challenges to forensic practitioners tasked with the analysis of drowned bodies. Postmortem changes in the marine environment have not been extensively investigated and the current literature is mainly based on bodies retrieved from shallow waters or on limited samples. On 18 April 2015, a fishing boat carrying allegedly 1,000 migrants sank in the Mediterranean Sea. In a fifteen-month time span, humanitarian missions were carried out to recover the bodies from the sea. The present study investigates postmortem changes on the drowned victims in a non-sequestered environment in the Mediterranean Sea. A retrospective study was performed by two observers on the autopsy photographic records in the series of bodies recovered from the open sea. For 184 bodies, the postmortem changes were evaluated according to facial, body, limb, and total aquatic decomposition score (FADS, BADS, LADS, TADS, respectively). Furthermore, a modification to the current scoring system that divides upper and lower limbs was suggested. The interobserver agreement was assessed using Krippendorff's alpha coefficient. Possible relations between the decomposition scores and PMSI were investigated with Pearson correlation analysis. According to the sequence of the recovery missions, increasing FADS, BADS, LADS, and TADS were observed. The modified scoring system showed a strong agreement between observers, allowing a more accurate description of the actual extent of decomposition. The scores showed a significant relation with the PMSI (p < 0.01). Prolonged submersion in the open marine environment was confirmed to show increasing decomposition rates, from moderate decay to full disarticulation. This study provides a descriptive unicum of the postmortem changes in the open sea, which may contribute to strengthen the discipline and aid description of bodies recovered in similar circumstances, especially if a body needs to be associated to a disaster or period with respect to another, thus facilitating families or authorities in the search for specific victims.

Importance of dashboard camera (Dash Cam) analysis in fatal vehicle-pedestrian crash reconstruction

The reconstruction of dynamic of traffic injuries remains a challenge in forensic pathology and is often based on circumstantial data. Dash Cams are digital video recorders which can be located inside a vehicle and continuously record the view through the windscreen, thus providing objective evidence. Here we present the case of a traffic crash in which a pedestrian was hit by an articulated lorry. The analysis of a video recorded from a Dash Cam retrieved inside the vehicle during the death scene investigation (DSI) was crucial in the reconstruction of the manner of death. Indeed, the death, which was initially assumed to be accidental, was finally deemed as a suicide on the basis of the video recording, which showed an intentional and sudden rush of the victim to the middle of the roadway. Advantages and disadvantages of the use of Dash Cams will be discussed, focusing on the profound differences in the related national and international regulations. Based on the present case, in traffic crashes, the search for Dash Cams during the DSI may be recommended and the video recordings should be analyzed in the setting of a multidisciplinary and multimodal evaluation of the case, for a proper reconstruction of the facts.

Outdoor human decomposition in Sweden: A retrospective quantitative study of forensic-taphonomic changes and postmortem interval in terrestrial and aquatic settings

This paper presents a quantitative retrospective study of gross human decomposition in central and southeastern Sweden. The applicability of methods developed abroad for postmortem interval (PMI) estimation from decomposition morphology and temperature are is evaluated. Ninety-four cases were analyzed (43 terrestrial and 51 aquatic) with a median PMI of 48 days. The results revealed differences in decomposition patterns between aquatic, surface, hanging, and buried remains. While partial saponification and desiccation occurred in cases of surface remains, complete skeletonization was observed in all cases with a PMI over two years. Aquatic skeletonization was slower due to extensive saponification in cases with PMI higher than one year. Formulae for assessing accumulated degree-days (ADD) from the original methods did not fit the study material. However, a regression analysis demonstrated that 80% of decomposition variance in surface remains could be explained by ADD, suggesting that a geographically adapted equation holds promise for assessing PMI. In contrast, the model fit was poor for aquatic cases (43%). While this may be explained by problems in obtaining reliant aquatic temperature data or an insufficient scoring system, aquatic decomposition may be highly dependent on factors other than ADD alone. This study evaluates the applicability of current PMI methods on an outdoor sample from a previously unpublished region, and represents the first scientific publication of human outdoor decomposition patterns in Sweden. Suggestions for future research are provided, including that scoring methods should incorporate saponification to fit forensic taphonomy in Swedish environments.