The Identified Skeletal Collection of the School of Legal Medicine: a contemporary osteological collection housed in Universidad Complutense de Madrid, Spain.

ABSTRA: Osteological collections are an important resource for the development of methods to assist in the study of skeletal remains in archeological and/or forensic contexts. The aim is to describe the current characteristics of the Identified Skeletal Collection of the School of Legal Medicine and its historical context. The Identified Skeletal Collection of the School of Legal Medicine of the Complutense University of Madrid consists of 138 male and 95 female individuals, born between 1880 and 1980 and deceased between 1970 and 2009. The minimum age of the sample is perinatal and the maximum age is 97 years. The collection is an essential tool for forensic research, given that its population characteristics can be extrapolated to those of present-day Spain. Access to this collection offers unique teaching opportunities as well as provides the information necessary to develop various lines of research.

Measuring dimensional and morphological heat alterations of dismemberment-related toolmarks with an optical roughness metre.

This experimental study provides a further understanding of the post-burning nature of sharp force trauma. The main objective is to analyse the distortion that fire may inflict on the length, width, roughness, and floor shape morphology of toolmarks induced by four different implements. To this end, four fresh juvenile pig long bones were cut with a bread knife, a serrated knife, a butcher machete, and a saw. A total of 120 toolmarks were induced and the bone samples were thus burnt in a chamber furnace. The lesions were analysed with a 3D optical surface roughness metre before and after the burning process. Afterwards, descriptive statistics and correlation tests (Student's t-test and analysis of variance) were performed. The results show that fire exposure can distort the signatures of sharp force trauma, but they remain recognisable and identifiable. The length decreased in size and the roughness increased in a consistent manner. The width did not vary for the saw, serrated knife, or machete toolmarks, while the bread knife lesions slightly shrunk. The floor shape morphology varied after burning, and this change became more noticeable for the three knives. It was also observed that the metrics of the serrated knife and machete cut marks showed no significant variations. Our results demonstrate that there is a variation in the toolmark characteristics after burning. This distortion is dependent on multiple factors that influence their dimensional and morphological changes, and the preservation of class features is directly reliant upon the weapon employed, the trauma caused, and the burning process conditions.

Cut or burnt? - Categorizing morphological characteristics of heat-induced fractures and sharp force trauma.

Distinguishing trauma from heat-induced fractures is a challenge faced by forensic anthropologists and pathologists during medicolegal investigations in which fire has been used by the perpetrators to destroy evidence. This paper aims to validate the provided identification features to distinguish between fire induced alterations and sharp force trauma. A total of 80 cremated adult individuals were used in this paper: 3 recently deceased embalmed cadavers from Cementerio Sur de Madrid for the sharp force trauma experiment in which 55 pre-burning injuries were inflicted using a machete and a serrated knife in different anatomical regions. And 77 cremated individuals from the Forensic Anthropology and Odontology Laboratory osteological collection. Five cremated long bones from this collection were selected, and 10 cuts were manually inflicted using a serrated knife to analyse post-burning trauma. Heat-induced changes and trauma morphologic characteristics were thus documented and analysed. The examination and documentation of morphological traits enabled the production of a heat-induced changes visual guide and a flow-chart. Two intraclass correlation tests were performed to validate the capacity of the observer to distinguish between fire related alterations and toolmarks. The results obtained in the statistical analysis indicate that, even if the toolmarks are visible and recognizable upon macroscopic observation by the observers, some features, such as the step and the transverse fractures can be mistaken with inflicted trauma. The use of the proposed features coupled with careful anthropological examination is recommended and has been found functional for participants with no prior knowledge in the analysis of cremated remains.

Through fire and flames: post-burning survival and detection of dismemberment-related toolmarks in cremated cadavers.

During a homicide investigation in which fire has been used to reduce the size of the cadaver and conceal the evidence of injuries, the identification of perimortem trauma presents a challenge, in particular in cases when the perpetrator has dismembered the body followed by burning the remains. It is therefore important to understand the effects which heat causes on fresh bone. The aim of this paper is to perform a pilot study on the survival ratio of toolmarks in different anatomical regions associated with dismemberment, and a descriptive analysis of the variables that may potentially influence the post-burning survival and detection. To achieve this, three donated embalmed cadavers were used to simulate a case in which an attempted dismemberment and burning had occurred. Fifty-five pre-burning injuries were manually induced: 30 using a machete to inflict chopping trauma, and 25 with a serrated bread knife to inflict sharp force trauma, on the thigh, knee, ankle and wrist. The cadavers were cremated in a furnace at Madrid's Cementerio Sur and the burnt remains were analysed at the Laboratorio de Antropología y Odontología Forense of the Universidad Complutense de Madrid. Not all pre-burning injuries inflicted were visible after the cremation process; only 13% were detected in this experiment. Toolmarks can be masked, modified, destroyed or overlooked from the outset of the procedure due to several factors which influence the post-burning survival and detection of toolmarks and contribute to conceal the evidence of trauma. Additional research should be done to study further variables which affect the post-burning visibility of sharp force trauma.