<p><strong>Abstract.</strong> Light field cameras record both the light intensity received by the sensor and the direction in which the light rays are travelling through space. Recording the additional information of the direction of Light rays provides the opportunity to refocus an image after acquisition. Furthermore, a depth image can be created, providing 3D information for each image pixel. Both, focused images and 3D information are relevant for forensic investigations. Basic overview images are often acquired by photographic novices and under difficult conditions, which make refocusing of images a useful feature to enhance information for documentation purposes. Besides focused images, it can also be useful to have 3D data of an incident scene. Capital crime scenes such as homicide are usually documented in 3D using laser scanning. However, not every crime scene can be identified as capital crime scene straight away but only in the course of the investigation, making 3D data acquisition of the discovery situation impossible. If this is the case, light field images taken during the discovery of the scene can provide substantial 3D data. We will present how light field images are refocused and used to perform photogrammetric reconstruction of a scene and compare the generated 3D model to standard photogrammetry and laser scanning data. The results show that refocused light field images used for photogrammetry can improve the photogrammetry result and aid photogrammetric processing.</p>
Occasional case reports have described isolated cases of conducted electrical weapon (CEW) probes piercing the human skull. In an experimental setting, we examined whether these cases were just unfortunate incidents, how deeply such probes can pierce the skull, and whether firing distance and CEW probe type play a role in the skull-piercing capability.We fired 5 different CEW cartridges (XP 10.6 m, XP 7.6 m, smart 10.6 m, smart 7.6 m, and smart probe 7.6 m) from 4 different distances (0.5, 1, 2, and 4 m) at head phantoms made of either 5-or 7-mm-thick polyurethane spheres covered with a thin layer of gelatine and buckskin. The piercing depths were recorded by computed tomographic scanning.All tested cartridges managed to pierce the head phantoms. Piercing depths of up to 6.6 mm in the 5-mm heads and depths of almost 5 mm in the 7-mm heads were recorded. Deepest piercing depths were attained with firing distances of 2 m or less.Our results showed that all tested CEW probes are capable of piercing the skull and that shorter firing distances tend to lead to deeper piercing depths.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.