Accuracy and Reproducibility of Bullet Trajectories in FARO Zone 3D

With three-dimensional (3D) laser scanning technology and software packages, the practice of documenting and measuring bullet trajectories has benefited from greater accuracy and reproducibility. This study investigated the accuracy and reproducibility of the bullet trajectory tools in the software package, FARO Zone 3D (FZ3D). Twelve participants were provided laser scanner data for 21 bullet trajectories on drywall panels with impact angles between 25° and 90°. When the impact plane was manually aligned by the operator, 75% of the absolute errors were within 0.91° and 0.98° for the azimuth and vertical angles, respectively. The vertical angle improved to 0.47° when impact plane alignment was taken with respect to gravity (no operator influence). Thus, manual alignment is shown to be subject to greater error than alignment with gravity. However, this study shows that the accuracy and reproducibility of the FZ3D bullet trajectory tools to be comparable with previous research studies.     

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.     

A Computational Framework for Age‐at‐Death Estimation from the Skeleton: Surface and Outline Analysis of 3D Laser Scans of the Adult Pubic Symphysis

In forensic anthropology, age‐at‐death estimation typically requires the macroscopic assessment of the skeletal indicator and its association with a phase or score. High subjectivity and error are the recognized disadvantages of this approach, creating a need for alternative tools that enable the objective and mathematically robust assessment of true chronological age. We describe, here, three fully computational, quantitative shape analysis methods and a combinatory approach that make use of three‐dimensional laser scans of the pubic symphysis. We report a novel age‐related shape measure, focusing on the changes observed in the ventral margin curvature, and refine two former methods, whose measures capture the flatness of the symphyseal surface. We show how we can decrease age‐estimation error and improve prior results by combining these outline and surface measures in two multivariate regression models. The presented models produce objective age‐estimates that are comparable to current practices with root‐mean‐square‐errors between 13.7 and 16.5 years.     

武汉汉族人群STR基因座D3S1358、D13S317、D12S391的多态性研究

目的　调查中国武汉地区汉族人群STR基因座—D3S1 358、D1 3S31 7、D1 2S391基因频率分布和群体遗传数据。方法　从 2 0 8个汉族无关个体收集血液标本 ,应用PCR技术及聚丙烯酰胺凝胶垂直板电泳对D3S1 358、D1 3S31 7和D1 2S391基因座分型。结果　D3S1 358检出 7个等位基因和 4 1个基因型。三基因座基因型分布符合Hardy-Weinberg平衡。观察 2 31次减数分裂均未发现突变基因。另外 ,调查结果计算显示D3S1 358、D1 3S31 7和D1 2S391基因座的杂合度 (H)分别为 0 70 98、 0 80 56和 0 84 0 0 ;三个人识别能力 (DP)分别为 0 851 6、 0 9332和 0 952 3;非父排除率 ( pE)分别为 0 4 463、 0 60 1 6和 0 681 8。结论　D3S1 358、D1 3S31 7和D1 2S391基因座在群体遗传学研究和法医学亲子鉴定及个人识别中具有较高实用价值