The detection of clandestine graves in an arid environment using thermal imaging deployed from an unmanned aerial vehicle

The Middle East is one of the world regions that has frequently suffered from armed conflicts that resulted in mass burials. However, the detection of clandestine graves in such an arid environment by deploying remote sensing payload on unmanned aerial vehicles (UAVs) has received little attention. The present study used a UAV equipped with a thermal sensor aimed at narrowing down the search area of possible gravesites in the arid climate of Kuwait. The enclosed research area, which includes both control and experimental mass graves, was imaged for 18 months. The variation in topsoil temperature and soil moisture between the graves and their surroundings was evaluated. The results of the analysis demonstrated the effectiveness of thermal imaging techniques in detecting heat produced from buried sheep carcasses and detecting the change in grave soil moisture for our research environment for 7 and 10 months, respectively. The buried animals significantly influenced the topsoil temperature (p = 0.044), while the height from which the images were captured had an insignificant effect on the measured temperature within the range tested (p = 0.985). Furthermore, there was a negative correlation (−0.359) between grave temperature and the calculated soil moisture. The results from these cost- and time-effective search methods presented in this study confirm their potential for the detection of burial sites in an arid environment.     

If Brain Scans Really Detected Deception,Who Would Volunteer to be Scanned?

Abstract: Recent neuroimaging studies investigating the neural correlates of deception among healthy people, have raised the possibility that such methods may eventually be applied during legal proceedings. Were this so, who would volunteer to be scanned? We report a “natural experiment” casting some light upon this question. Following broadcast of a television series describing our team’s investigative neuroimaging of deception in 2007, we received unsolicited (public) correspondence for 12 months. Using a customized template to examine this material, three independent assessors unanimously rated 30 of an initial 56 communications as unequivocally constituting requests for a “scan” (to demonstrate their author’s “innocence”). Compared with the rest, these index communications were more likely to originate from incarcerated males, who were also more likely to engage in further correspondence. Hence, in conclusion, if neuroimaging were to become an acceptable means of demonstrating innocence then incarcerated males may well constitute those volunteering for such investigation.     

Using Spatial,Temporal and Evidence‐status Data to Improve Ballistic Imaging Performance

Firearms identification imaging systems help solve crimes by comparing newly acquired images of cartridge casings or bullets to a database of images obtained from past crime scenes. We formulate an optimization problem that bases its matching decisions not only on the similarity between pairs of images, but also on the time and spatial location of each new acquisition and each database entry. The objective is to maximize the detection probability subject to a constraint on the false positive rate. We use data on all cartridge casings matches detected in Israel during 2006–2008 to estimate most of the model parameters. We estimate matching accuracy from two different studies and predict that the optimal use of extraneous information would increase the detection probability from 0.931 to 0.987 and from 0.707 to 0.844, respectively. These improvements are achieved by favoring pairs of images that are closer together in space and time.     

The application of infrared chemical imaging to the detection and enhancement of latent fingerprints: method optimization and further findings

Fourier transform infrared (FTIR) chemical imaging allows the collection of fingerprint images from backgrounds that have traditionally posed problems for conventional fingerprint detection methods. In this work, the suitability of this technique for the imaging of fingerprints on a wider range of difficult surfaces (including polymer banknotes, various types of paper, and aluminum drink cans) has been tested. For each new surface, a systematic methodology was employed to optimize settings such as spectral resolution, number of scans, and pixel aggregation in order to reduce collection time and file-size without compromising spatial resolution and the quality of the final fingerprint image. The imaging of cyanoacrylate-fumed fingerprints on polymer banknotes has been improved, with shorter collection times for larger image areas. One-month-old fingerprints on polymer banknotes have been successfully fumed and imaged. It was also found that FTIR chemical imaging gives high quality images of cyanoacrylate-fumed fingerprints on aluminum drink cans, regardless of the printed background. Although visible and UV light sources do not yield fingerprint images of the same quality on difficult, nonporous backgrounds, in many cases they can be used to locate a fingerprint prior to higher quality imaging by the FTIR technique. Attempts to acquire FTIR images of fingerprints on paper-based porous surfaces that had been treated with established reagents such as ninhydrin were all unsuccessful due to the swamping effect of the cellulose constituents of the paper.     

The Accuracy and Applicability of 3D Modeling and Printing Blunt Force Cranial Injuries

The purpose of this study was to determine the factors affecting the accuracy of 3D models and 3D prints of cranial blunt force trauma, to evaluate the applicability and limitations of modeling such injuries. Three types of cranial blunt force lesions were documented (hinge, depressed, and comminuted) using three forms of surface scanning (laser, structured light scanner, and photogrammetry) at two different quality settings (standard and high). 3D printed models of the lesions were produced using two different materials (a gypsum‐like composite powder called VisiJet^® PXL and an acrylic engineered composite plastic called VisiJet^® M3 in crystal colour). The results of these analyzes indicate the prints in this study exhibit some statistically significant differences from the actual bone lesions, but details of the lesions can be reproduced to within 2 mm accuracy.     

Forensic Imaging‐Guided Recovery of Nuclear DNA from the Spinal Cord*,†

Abstract: Our objective is to document the recovery of DNA from the spinal cord or surrounding dura mater in 11 cases of severely burned human remains. Radiographs established that portions of charred tissue contained spine segments. Multidetector computed tomography (MDCT) revealed that each spine specimen contained an intact spinal cord remnant. A full DNA profile was obtained from seven specimens using spinal cord dura mater in six specimens and spinal cord medulla in one specimen. A partial profile was obtained from four specimens (spinal cord dura mater, 2; spinal cord medulla, 2). Bone and muscle surrounding the spinal cord appear to insulate nucleic acid containing tissue from critical thermal degradation. The spinal cord, which is easily identified by MDCT examination of remains and easily recovered at the postmortem examination, can be a source of DNA with extraction yields comparable with other tissue sources. Specimens of dura mater are preferable as processing time is faster than bone.     

Differentiation of Antemortem and Postmortem Appendicular Fractures Using Magnetic Resonance Imaging Signal Intensity Changes in Bone and Soft Tissues,

Intraosseous T1-weighted (T1W) and short-tau inversion recovery (STIR) magnetic resonance imaging (MRI) signal intensity changes—so-called bone marrow edema—may be able to differentiate antemortem and postmortem fractures in human forensic imaging. The primary objective of this study was to investigate this hypothesis using an animal model. Three juvenile Landrace pigs were anesthetized and underwent MRI of both tibiae and both radii using a 1.5 T magnet. T1W, T2-weighted (T2W), STIR, and T2* sequences were included. Antemortem fractures were induced in both tibiae and postmortem fractures in both radii, and MRI was repeated. Two board-certified radiologists blinded to fracture group jointly evaluated the images for intraosseous and soft tissue signal intensity changes. Sensitivity (Se) and specificity (Sp) in identifying antemortem fractures were calculated based on intraosseous, soft tissue, and combined intraosseous and soft tissue signal intensity changes. Intraosseous and soft tissue signal intensity changes, when present, were hyperintense in all sequences. Intraosseous hyperintensity in T1W and T2W sequences yielded Sp of 100% for antemortem fractures. Regardless of sequence, soft tissue hyperintensity was comparatively more sensitive than intraosseous hyperintensity. Sensitivity for each sequence could be maximized by assessment of soft tissue and intraosseous hyperintense signals together; for the T1W sequence, such assessment optimized diagnostic utility yielding a Se of 100% and Sp of 83%. In summary, MRI—particularly the T1W sequence—can differentiate antemortem and postmortem fractures and may be a useful adjunct to the forensic analyses of fractures.     

尸体断层影像学文献计量分析

尸体断层影像学(post-mortem cross-sectional imaging,PMCSI),也称虚拟解剖(virtopsy)或解剖画像(Ai),是法医学的革命性技术。较国际而言,我国PMCSI领域发展相对缓慢。进行系统的PMCSI文献计量分析研究,对于厘清国际PMCSI发展整体概貌和制定我国PMCSI发展战略方面,有着重要的现实意义。本文通过对2013-2019年PMCSI领域下27个专业术语不同组合进行在线文献搜索,并对文献的年份、作者、研究领域、发表杂志、作者单位、发表国家等系列指标进行了定性定量分析。分析结果表明世界PMCSI发展迅速:PMCSI已成为国际法医学的研究热点;瑞士、日本和英国PMCSI研究位居世界领先地位;尸体计算机断层扫描、尸体计算机断层扫描血管造影和尸体磁共振成像三个领域研究最为深入;PMCSI研究已得到相关学界的认同;法医日常检案中普及PMCSI是世界发展趋势。     

磁敏感加权成像在出血性弥散性轴索损伤鉴定中的应用

目的探讨磁敏感加权成像(susceptibility weighted imaging,SWI)在出血性弥散性轴索损伤(diffuse axonal injury,DAI)法医学鉴定中的应用价值。方法对20例DAI的法医学鉴定资料进行回顾性分析,对其T1WI、T2WI、扩散加权成像(diffusion weighted imaging,DWI)、液体衰减反转恢复(fluid attenuated inversion recovery,FLAIR)、磁敏感加权成像(susceptibility weighted imaging,SWI)序列影像资料进行统计分析。结果 DAI出血灶多位于脑组织表浅区,SWI对出血性DAI的检出率最高,与其他序列成像之间的差异有统计学意义(P0.05)。结论 SWI在DAI法医学鉴定中具有重要的意义。     

Visualization of latent fingerprints using fluorescence lifetime imaging on paper emitting strong fluorescence

Latent fingerprints were successfully visualized using fluorescence lifetime imaging (FLIM) on paper which emits strong fluorescence with a lifetime close to that of fingerprints and thus from which it is difficult for time-resolved spectroscopy to visualize fingerprints. Latent fingerprint samples on paper were excited using a 450 nm or 532 nm nanosecond pulsed-laser, and time-resolved fluorescence images were obtained at a delay time of 6–16 ns in intervals of 1 ns, to the excitation pulse. The excitation beam was expanded using a lens, and the fluorescence from the fingerprints was captured using an intensified CCD camera. Because of the large fluorescence intensity of the background paper of approximately two to four orders of magnitude larger than that of the fingerprint, the fingerprint was not visualized on each fluorescence image by time-resolved spectroscopy. However, the fingerprint was visualized in a FLIM image constructed using a series of the fluorescence images for the case with the fluorescence intensity of the background paper being four orders of magnitude larger than that of the fingerprint. The difference in fluorescence lifetime in the FLIM image of the visualized fingerprint and background paper was in the order of 0.1 ns, which was an order of magnitude smaller than the inherent fluorescence lifetime of a few nanoseconds for the fingerprints and paper. It was demonstrated that, at a background fluorescence intensity with a certain order of magnitude larger than that of fingerprints, FLIM has the potential to visualize latent fingerprints which cannot be visualized by time-resolved spectroscopy.