Hołowko Elwira, Januszkiewicz Kamil, Bolewicki Paweł, Sitnik Robert, Michoński Jakub
Virtual Reality Techniques Division, Institute of Micromechanics and Photonics, Warsaw University of Technology, 8 Boboli Street, Warsaw, Poland.
Central Forensic Laboratory of the Police R&D, 14 Iwicka Street, Warsaw, Poland.
Forensic Sci Int. 2016 Oct;267:218-227. doi: 10.1016/j.forsciint.2016.08.036. Epub 2016 Sep 9.
In forensic documentation with bloodstain pattern analysis (BPA) it is highly desirable to obtain non-invasively overall documentation of a crime scene, but also register in high resolution single evidence objects, like bloodstains. In this study, we propose a hierarchical 3D scanning platform designed according to the top-down approach known from the traditional forensic photography. The overall 3D model of a scene is obtained via integration of laser scans registered from different positions. Some parts of a scene being particularly interesting are documented using midrange scanner, and the smallest details are added in the highest resolution as close-up scans. The scanning devices are controlled using developed software equipped with advanced algorithms for point cloud processing. To verify the feasibility and effectiveness of multi-resolution 3D scanning in crime scene documentation, our platform was applied to document a murder scene simulated by the BPA experts from the Central Forensic Laboratory of the Police R&D, Warsaw, Poland. Applying the 3D scanning platform proved beneficial in the documentation of a crime scene combined with BPA. The multi-resolution 3D model enables virtual exploration of a scene in a three-dimensional environment, distance measurement, and gives a more realistic preservation of the evidences together with their surroundings. Moreover, high-resolution close-up scans aligned in a 3D model can be used to analyze bloodstains revealed at the crime scene. The result of BPA such as trajectories, and the area of origin are visualized and analyzed in an accurate model of a scene. At this stage, a simplified approach considering the trajectory of blood drop as a straight line is applied. Although the 3D scanning platform offers a new quality of crime scene documentation with BPA, some of the limitations of the technique are also mentioned.
在涉及血迹形态分析（BPA）的法医文件记录中，非常希望能以非侵入性方式获取犯罪现场的全面文件记录，同时还要对单个证据物品（如血迹）进行高分辨率记录。在本研究中，我们提出了一个分层3D扫描平台，该平台是根据传统法医摄影中已知的自上而下方法设计的。通过整合从不同位置注册的激光扫描来获取场景的整体3D模型。使用中程扫描仪对场景中特别有趣的一些部分进行记录，并以高分辨率特写扫描添加最小的细节。使用配备有先进点云处理算法的开发软件来控制扫描设备。为了验证多分辨率3D扫描在犯罪现场文件记录中的可行性和有效性，我们的平台被应用于记录由波兰华沙警察研发中心中央法医实验室的BPA专家模拟的一个谋杀现场。应用3D扫描平台在结合BPA的犯罪现场文件记录中被证明是有益的。多分辨率3D模型能够在三维环境中对场景进行虚拟探索、距离测量，并能更真实地保存证据及其周围环境。此外，在3D模型中对齐的高分辨率特写扫描可用于分析犯罪现场发现的血迹。BPA的结果（如轨迹和起源区域）在准确的场景模型中进行可视化和分析。在这个阶段，应用了一种将血滴轨迹视为直线的简化方法。尽管3D扫描平台为结合BPA的犯罪现场文件记录提供了新的质量，但也提到了该技术的一些局限性。
