An Overview of 3D Printing in Forensic Science: The Tangible Third-Dimension

There has been a rapid development and utilization of three-dimensional (3D) printing technologies in engineering, health care, and dentistry. Like many technologies in overlapping disciplines, these techniques have proved to be useful and hence incorporated into the forensic sciences. Therefore, this paper describes how the potential of using 3D printing is being recognized within the various sub-disciplines of forensic science and suggests areas for future applications. For instance, the application can create a permanent record of an object or scene that can be used as demonstrative evidence, preserving the integrity of the actual object or scene. Likewise, 3D printing can help with the visualization of evidential spatial relationships within a scene and increase the understanding of complex terminology within a courtroom. However, while the application of 3D printing to forensic science is beneficial, currently there is limited research demonstrated in the literature and a lack of reporting skewing the visibility of the applications. Therefore, this article highlights the need to create good practice for 3D printing across the forensic science process, the need to develop accurate and admissible 3D printed models while exploring the techniques, accuracy and bias within the courtroom, and calls for the alignment of future research and agendas perhaps in the form of a specialist working group.     

Building faces from dry skulls: are they recognized above chance rates?

Methods of facial approximation have successfully aided the identification of deceased individuals. Successes may be due to either accurate facial approximation techniques or chance. This study aims to determine if any of 16 facial approximations, built using standard techniques, are sufficiently accurate to produce correct identifications of target individuals above chance. Four skulls were approximated using four commonly used methods of facial approximation. The resulting 16 facial approximations were judged by 37 assessors of varying ages. Assessors attempted to identify the target individual of each facial approximation from a face pool of ten photographed faces. Only one facial approximation resulted in true positive identification rates above chance at statistically significant levels. It is concluded that it is rare for facial approximations to be sufficiently accurate to allow identification of a target individual above chance. Since 403 incorrect identifications were made out of 592 identification scenarios, facial approximation should be considered to be a highly inaccurate and unreliable forensic technique. These results suggest that facial approximations are not very useful in excluding individuals to whom skeletal remains may not belong. Evidence from this experiment supports suggestions by others that facial approximation should be used in forensic science when all other methods of identification have failed and only to provide tentative identification.     

Three-dimensional computer visualization of forensic pathology data

Despite a decade of use in US courtrooms, it is only recently that forensic computer animations have become an increasingly important form of communication in legal spheres within the United Kingdom. Aims Research at the University of Nottingham has been influential in the critical investigation of forensic computer graphics reconstruction methodologies and techniques and in raising the profile of this novel form of data visualization within the United Kingdom. The case study presented demonstrates research undertaken by Aims Research and the Department of Forensic Pathology at the University of Sheffield, which aims to apply, evaluate, and develop novel 3-dimensional computer graphics (CG) visualization and virtual reality (VR) techniques in the presentation and investigation of forensic information concerning the human body. The inclusion of such visualizations within other CG or VR environments may ultimately provide the potential for alternative exploratory directions, processes, and results within forensic pathology investigations.     

Public beliefs about the accuracy and importance of forensic evidence in the United States

Recent advances in forensic science, especially the use of DNA technology, have revealed that faulty forensic analyses may have contributed to miscarriages of justice. In this study we build on recent research on the general public’s perceptions of the accuracy of 10 forensic science techniques and of each stage in the investigation process. We find that individuals in the United States hold a pessimistic view of the forensic science investigation process, believing that an error can occur about half of the time at each stage of the process. We find that respondents believe that forensics are far from perfect, with accuracy rates ranging from a low of 55% for voice analysis to a high of 83% for DNA analysis, with most techniques being considered between 65% and 75% accurate. Nevertheless, respondents still believe that forensic evidence is a key part of a criminal case, with nearly 30% of respondents believing that the absence of forensic evidence is sufficient for a prosecutor to drop the case and nearly 40% believing that the presence of forensic evidence – even if other forms of evidence suggest that the defendant is not guilty – is enough to convict the defendant.     

Adherence of forensic odontologists to the ABFO guidelines for victim evidence collection

Certifying boards for different professions have the duty to help establish standards and guidelines for methodologies routinely performed within the discipline. For forensic dentists, this responsibility is placed upon the American Board of Forensic Odontology (ABFO). The purpose of this study was to examine whether board certified and noncertified forensic odontologists adhere to the ABFO Guidelines outlined in the collection of victim bitemark evidence. A questionnaire was developed to assess the compliance and attitudes towards the typical evidence collected, the photographic documentation, and the handling of the bite site injury. The results indicate the majority of the respondents in both representative groups routinely follow the guidelines set forth by the ABFO. The lack of personally photographing the bite injury on a consistent basis is an area of concern for all examiners. The photographic evidence is an instrumental part of the investigation and often cannot be utilized due to improper procedures being followed. The film type utilized, bite site impression techniques, and excision of any tissue samples remain an individual choice and vary significantly among each forensic odontologist.     

Particle size analysis of sediments, soils and related particulate materials for forensic purposes using laser granulometry

Particle size is a fundamental property of any sediment, soil or dust deposit which can provide important clues to nature and provenance. For forensic work, the particle size distribution of sometimes very small samples requires precise determination using a rapid and reliable method with a high resolution. The Coulter trade mark LS230 laser granulometer offers rapid and accurate sizing of particles in the range 0.04-2000 microm for a variety of sample types, including soils, unconsolidated sediments, dusts, powders and other particulate materials. Reliable results are possible for sample weights of just 50 mg. Discrimination between samples is performed on the basis of the shape of the particle size curves and statistical measures of the size distributions. In routine forensic work laser granulometry data can rarely be used in isolation and should be considered in combination with results from other techniques to reach an overall conclusion.     

Forensic medicine experiences in Kosovo

In summer 1999, a German forensic team of CID officers and forensic pathologists was sent to Kosovo on request of the International Criminal Tribunal for the former Yugoslavia (ICTY) to investigate possible war crimes. For this purpose, witnesses had to be found and interrogated and graves of victims had to be located and the bodies exhumed and examined forensically. Roughly 200 bodies have been found and examined during the campaign that were predominantly of male sex and showed mainly gunshot wounds. A high percentage of all bodies could be identified. The article deals with different forensic-pathologic aspects of such an investigation.     

An improved protocol for the examination of rogue WWW sites

Internet server managers have a range of techniques available to help them improve service performance and security. These techniques can become barriers to the investigation of illicit or illegal activity. This paper describes some of the legitimate techniques which can be used to improve server performance or security, and which present challenges for the investigator. Furthermore, it proposes a rigorous procedure which should be followed to ensure that any investigation of a web site or server has been complete and accurate, and that all possible useful information has been extracted and examined.     

46例尺骨鹰嘴骨折法医学鉴定分析

探讨尺骨鹰嘴骨折 ,术后于功能位制动患者进行法医学鉴定的时间。对 46例尺骨鹰嘴骨折患者进行随访 ,观察在不同时期肘关节功能恢复情况。伤后 3～ 4个月 ,肘关节功能可恢复到 40°～ 90°活动范围 ;伤后 6～ 8个月 ,关节活动范围可达 70°～ 12 0° ;伤后 10～ 12个月 ,关节活动范围可达到 110°～ 14 0°。尺骨鹰嘴骨折术后于功能位制动患者 ,3个月后即可进行法医学鉴定。此期 ,肘关节功能不但有了一定程度的恢复 ,骨折亦临床愈合 ,关节较稳定有力。     

Getting in touch--3D printing in forensic imaging

With the increasing use of medical imaging in forensics, as well as the technological advances in rapid prototyping, we suggest combining these techniques to generate displays of forensic findings. We used computed tomography (CT), CT angiography, magnetic resonance imaging (MRI) and surface scanning with photogrammetry in conjunction with segmentation techniques to generate 3D polygon meshes. Based on these data sets, a 3D printer created colored models of the anatomical structures. Using this technique, we could create models of bone fractures, vessels, cardiac infarctions, ruptured organs as well as bitemark wounds. The final models are anatomically accurate, fully colored representations of bones, vessels and soft tissue, and they demonstrate radiologically visible pathologies. The models are more easily understood by laypersons than volume rendering or 2D reconstructions. Therefore, they are suitable for presentations in courtrooms and for educational purposes.     

The relevance of the evolution of experimental studies for the interpretation and evaluation of some trace physical evidence

In order for trace evidence to have a high evidential value, experimental studies which mimic the forensic reality are of fundamental importance. Such primary level experimentation is crucial to establish a coherent body of theory concerning the generation, transfer and persistence of different forms of trace physical evidence. We contend that the forensic context, at whatever scale, will be specific to each individual forensic case and this context in which a crime takes place will influence the properties of trace evidence. It will, therefore, be necessary in many forensic cases to undertake secondary level experimental studies that incorporate specific variables pertinent to a particular case and supplement the established theory presented in the published literature. Such studies enable a better understanding of the specific forensic context and thus allow more accurate collection, analysis and interpretation of the trace physical evidence to be achieved.This paper presents two cases where the findings of secondary level experimental studies undertaken to address specific issues particular to two forensic investigations proved to be important. Specific pre-, syn- and post-forensic event factors were incorporated into the experimental design and proved to be invaluable in the recovery, analysis and in achieving accurate interpretations of both soil evidence from footwear and glass trace evidence from a broken window.These studies demonstrate that a fuller understanding of the specific context within which trace physical evidence is generated and subsequently collected, as well as an understanding of the behaviour of certain forms of trace physical evidence under specific conditions, can add evidentiary weight to the analysis and interpretation of that evidence and thus help a court with greater certainty where resources (time and cost) permit.     

论司法鉴定机构的公益性建设

从属性上分析。司法鉴定应当是政府着力提供的一种公共服务,具有公益属性,作为司法鉴定依托的司法鉴定机构应该以公益性建设为主导的价值方向。为侦查服务的侦查机关内设鉴定机构具有天然的公益性,但实践中出现的一系列问题也使其公益性出现偏位．从而引起人们对其公益性的质疑。在全国人大常委会《关于司法鉴定管理问题的决定》指引下的司法鉴定机构建设过程中,应该避免社会司法鉴定机构走向市场化的竞争域,从而保障鉴定意见这一法定证据的公正性、客观性和中立性。从现行鉴定体制出发,以建设国立司法鉴定机构为向导,使司法鉴定机构走向公益性的良性发展道路．是所要探讨的一个核心问题。国家级司法鉴定机构的公布,标志着我国司法鉴定机构公益性建设的开端．以此为契机,应认真思考公益性建设的进路。     

Turf wars: authority and responsibility for the investigation of mass graves

Mass graves are complex products of large-scale crimes. Such scenes pose four conceptual challenges to investigators and forensic experts: the individual victim, the crime, the setting, and the statistical. Exhumation and post-mortem examination of mortal remains with associated personal and forensic evidence require integrated management of core forensic personnel including investigators, archaeologists, anthropologists, odontologists and pathologists, among whom there is overlapping expertise. The key to avoiding competition and ill-will among experts is to recognize that all such experts should be enabled to make known how their expertise matches with the temporal and spatial boundaries of victim, crime and setting. In turn, they should be apprised of where they fit into the overall judicial process and their limits within the investigation. Consequently, each expert requires access to the factual background of the case, to the site and its contents throughout the investigation. Each forensic team member has a responsibility to influence the investigation--throughout its course when possible--to make findings within their areas of expertise, and to make these available to the rest of the team so as to contribute most meaningfully to the aims of the investigation, both forensic and humanitarian. The on-site crime scene manager has an overarching role to enable integrated access to the complete scene and its contents by each forensic expert team member. In other words, the forensic scientist is given access and the ability to influence the investigation while control of evidence from the site as to identity and criminal activity are maintained by the crime scene manager. This contribution is directed at both the crime scene manager and each forensic expert; it describes the essential spatial and temporal parameters of an expert's opinion so as to encourage cooperation, and discourage conflict, within the forensic team.     

侦查机关内设鉴定机构的负面影响与消解

侦查活动的特殊性使其染指于司法鉴定,侦查机关基于侦查工作之必要内设鉴定机构。侦查机关内设的鉴定机构又因侦查的追诉性质在鉴定活动中难以保持中立性,致使侦查机关的鉴定机构的性质与法律的中立性要求出现一些紧张关系,在诉讼中造成了一些负面影响。司法鉴定制度的改革旨在借助司法行政部门对司法鉴定的统一管理来催生侦查机关的鉴定机构和侦查活动相分离,从而保持侦查机关的鉴定机构具有相对的独立性,并通过制度调整后的外在监督力量与程序的制约机制来缓解这一紧张关系,以促进侦查机关的鉴定机构在诉讼中真正发挥发现事实真相的作用。     

烧骨组织形态变化及DNA技术在个体识别中的应用

烧骨在火灾、焚尸、交通、爆炸等案件和事故的检材中具有特殊的地位。通过对不同条件焚烧下烧骨组织形态及DNA变化规律的研究,可为法医实践中烧骨的种属鉴定、性别及年龄判定提供准确的依据和标准,同时可利用残存的基因位点对烧骨残块进行个体识别和同一认定。烧骨DNA的提取方法及检测技术也在不断探索和改进。本文对烧骨在形态学、组织学和分子生物学水平研究进展以及烧骨评测的方法、技术进行概述,旨在为法医实践及进一步研究提供新的方法和思路。     

Multi-technique comparison of source and primary transfer soil samples: an experimental investigation by D Croft and K Pye. A comment.

The Croft and Pye paper has a story to tell about the differentiation capabilities of four analytical techniques. It is not however, the whole story. This may be due in part to the lack of reproducibility in the generation of results, and also in the effort to match soil samples and thus infer that the results provide stronger conclusions than is possible to make with this sort of analysis. More research must be done to establish in what instances these techniques and others provide reliable, reproducible, representative and accurate results, and in what capacity such results can be presented. As they stand, the results from this paper should be treated with great caution and not extrapolated to any other forensic case work until greater reliability of these and other techniques has been established.