Micro-CT in a forensic examination of a fatal child abuse case: A case report.

Child abuse is a serious concern that can cause the death of a child. In such cases the medico-legal evidence is often pivotal but complex, drawing across multiple medical disciplines and techniques. One key specialism is histopathology, which is considered the gold standard for estimating the age of individual fractures. Another is micro-CT imaging, which can visualise the location of trauma across the body. This case report demonstrates how micro-CT was used to contextualise the histological evidence in the Criminal Justice Proceedings of a fatal child abuse case. This was achieved by overlaying the aged fracture evidence from histopathology onto the visuals rendered from micro-CT imaging. The case was a suspected child abuse of a deceased 1-month old infant who was reported unresponsive by their parents. The child was taken to hospital where they were pronounced dead. Suspicion was raised and post-mortem imaging confirmed head trauma and rib fractures, and the case was escalated for a forensic investigation. This case report details how the micro-CT imaging was merged with the gold standard of histopathology for visualisation of trauma, and how the court presentation was planned alongside Senior Investigating Officers and various medical experts. The presentation was used in court by the histopathologist to present the evidence. The resulting presentation provided additional clarity to jury members regarding the location, severity, frequency, and timings of the injuries. From the perspective of the investigating police force, the resulting presentation was crucial in ensuring understanding of the medico-legal evidence of how the infant died. The prosecuting lawyer noted that combining the histological and micro-CT evidence in this way allowed the evidence to be presented in a sensitive, clear, and impactful manner.

Advantages of micro-CT in the case of a complex dismemberment.

This case study reports the advantages of micro-CT to aid the investigative process in a complex dismemberment case. Micro-CT was successfully implemented to scan all skeletal remains of a dismembered female. The digital models were utilized to (i) screen for any further injuries not related to the dismemberment, (ii) provide measurements from false starts non-destructively, and (iii) visually represent the evidence in a structured format in court to improve the understanding of the forensic evidence by the jury. Acquiring high-resolution scans in this manner improved the efficiency of the forensic investigation by screening the remains and provided complementary toolmark evidence to the investigating team and forensic pathologist. A total of 14 false starts were identified along with the directionality of each dismemberment cut. Furthermore, the visual 3D representation of the remains in court provided a powerful tool to communicate this important evidence to the jury and form a prosecution narrative. As a forensic radiological method, micro-CT provided valuable information both in the investigation and the court presentation.

Micro-CT for the examination of paediatric rib injuries: A case series.

Cases of child abuse and homicide are amongst the biggest challenges investigators face, with complex evidence bases often strongly contested and reliant on specialist interpretation of the medical evidence. In many cases, this medical evidence includes examination of the deceased's skeleton using different macroscopic and microscopic imaging methods. Rib fractures are a common concern when examining suspicious cases and much research has been conducted on their causes. The role of CPR in particular has been controversial and therefore a clear assessment of the fracture distribution is crucial. Recent studies have shown the benefit of imaging techniques such as Computed Tomography, although the gold standard remains histology. This paper presents three cases of suspected non-accidental rib fractures of infants which had been examined using micro-CT and histology. Micro-CT has been shown to be superior to medical CT as it achieves a greater resolution, making it effective for paediatric post-mortem imaging. Micro-CT observations were compared retrospectively to the histology, which demonstrated that micro-CT found 69% of the fractures identified histologically as well as an additional 22% not identified through histology. As well as complimenting histological analysis, the extent to which micro-CT can enhance the overall examination of paediatric non-accidental injuries is also discussed.

Forensic 3D printing from micro-CT for court use- process validation.

Forensic application of 3D scanning and printing technology is gaining momentum with 3D printed evidence starting to be produced for court. However, the processes for creating these forensic 3D models requires still rigorous assessment to ensure they adhere to the relevant legal standards. Although, previous work has examined the accuracy of 3D prints created from medical grade Computed Tomography (CT), no such assessment has been carried out for Micro Computed Tomography (micro-CT) which offers superior resolution and the ability to capture forensically relevant injuries. This study aimed to quantify the error rates associated with forensic 3D printed models and toolmarks, created using three different printing technologies, based on micro-CT data. Overall, 3D printed models, based on micro-CT scans, replicate bone surface geometry to sub-millimetre accuracy (<0.62mm for overall shape and <0.36mm for toolmarks). However, there were significant differences between the printing technology employed (mean errors of -0.3%, -0.8%, and 0.7% for shape geometry and -0.8%, 14.1%, and 0.7% for toolmark geometry for Printers 1-3 respectively). Where possible, the authors recommend micro-CT imaging for producing forensic 3D printed bone models particularly when injuries are present.

A Holistic Multi-Scale Approach to Using 3D Scanning Technology in Accident Reconstruction.

Three-dimensional scanning and documentation methods are becoming increasingly employed by law enforcement personnel for crime scene and accident scene recording. Three-dimensional documentation of the victim's body in such cases is also increasingly used as the field of forensic radiology and imaging is expanding rapidly. These scanning technologies enable a more complete and detailed documentation than standard autopsy. This was used to examine a fatal pedestrian-vehicle collision where the pedestrian was killed by a van while crossing the road. Two competing scenarios were considered for the vehicle speed calculation: the pedestrian being projected forward by the impact or the pedestrian being carried on the vehicle's bonnet. In order to assist with this, the impact area of the accident vehicle was scanned using laser surface scanning, the victim was scanned using postmortem CT and micro-CT and the data sets were combined to virtually match features of the vehicle to injuries on the victim. Micro-CT revealed additional injuries not previously detected, lending support to the pedestrian-carry theory.

Using micro-computed tomography to examine the larynx in cases of suspected strangulation-a comparison of case findings and control images.

The examination of strangulation is one of the most challenging causes of death diagnoses encountered in forensic pathology. The injuries are often subtle and difficult to detect, especially in cases that lack superficial marks. Fractures of the laryngeal skeleton are commonly regarded as evidence of strangulation but these can be too subtle to be detected during autopsy. Micro-CT is a novel imaging technique that achieves a spatial resolution 1 µm or less which lends itself to the examination of small and delicate structures such as the larynx. However, there is little information to date regarding the appearance of the larynx at this scale, thus complicating the interpretation of the micro-CT images. This study therefore uses micro-CT to examine ten larynges from strangulation deaths and to compare them to nineteen samples from donor individuals in order to distinguish between naturally occurring features and actual trauma. It was found that there are several features which mimic damage in the donor group. Using associated case information, initial trends and patterns of different strangulation methods were established.

Using histology to evaluate micro-CT findings of trauma in three post-mortem samples - First steps towards method validation.

Forensic imaging technology has rapidly advanced over the past several decades and is gaining increasing significance in medico-legal death investigations. Medical-grade computed tomography (CT) is now routinely used in post-mortem examinations at numerous institutions across the globe. However, the resolution of medical-grade CT is limited and unsuitable when used to depict some smaller anatomical structures or micro-trauma. High-resolution micro-CT offers up to 100× the resolution to overcome this problem but is a very recent addition to the field of forensic radiology. Few studies so far have attempted to validate the results which is an essential prerequisite for it to be used in the criminal justice process as demanded by regulatory bodies. This study directly compares micro-CT images with histology, the current gold standard. Three cases were examined: two larynges from suspected strangulations and one ribcage of a case of fatal child abuse. A strong correlation was observed between histology and micro-CT as the majority of skeletal injuries were identified correctly. This paper discusses the forensic implications of the results and how micro-CT is complementary to histology.

Introducing 3D Printed Models as Demonstrative Evidence at Criminal Trials.

This case report presents one of the first reported uses of a 3D printed exhibit in an English homicide trial, in which two defendants were accused of beating their victim to death. The investigation of this crime included a micro-CT scan of the victim's skull, which assisted the pathologist to determine the circumstances of the assault, in particular regarding the number of assault weapons and perpetrators. The scan showed two distinct injury shapes, suggesting the use of either two weapons or a single weapon with geometrically distinct surfaces. It subsequently served as the basis for a 3D print, which was shown in court in one of the first examples that 3D printed physical models have been introduced as evidence in a criminal trial in the United Kingdom. This paper presents the decision-making process of whether to use 3D printed evidence or not.

Novel application of three-dimensional technologies in a case of dismemberment.

This case study reports the novel application of three-dimensional technologies such as micro-CT and 3D printing to the forensic investigation of a complex case of dismemberment. Micro-CT was successfully employed to virtually align severed skeletal elements found in different locations, analyse tool marks created during the dismemberment process, and virtually dissect a charred piece of evidence. High resolution 3D prints of the burnt human bone contained within were created for physical visualisation to assist the investigation team. Micro-CT as a forensic radiological method provided vital information and the basis for visualisation both during the investigation and in the subsequent trial making it one of the first examples of such technology in a UK court.

Developing the use of Structure-from-Motion in mass grave documentation.

Methods for mass-grave documentation have changed markedly since the first forensic investigations nearly 70 years ago. Recently, however, there has been little advancement in developing new and better methodology, especially when compared to other forensic disciplines and even within traditional archaeology. This paper proposes a new approach, using 3D modelling for the documentation and eventual analysis of mass-graves. Structure-from-Motion (SfM), which creates digital 3D models from a set of still photographs, was tested on a small, simulated mass grave. The results of this test suggest that the method offers resolution previously unavailable to mass-grave investigators, and facilitates stronger analytical potential than the more traditional methods. Further tests are needed to validate these methods, but these initial findings are promising and their application could enhance our knowledge of mass grave dynamics.