Forensic terrestrial photogrammetry from a single image

3D reconstruction of events: Search for a spatial correlation between injuries and the geometry of the body discovery site

The aim of the study was to assess the usefulness of analysing visual material in a 3D environment when examining spatial interrelations between the incident participants, tools, and space surrounding the incident site. Such analysis may provide information about the trauma mechanism, which may lead to the determination of probable events. This paper points to the potential of conducting research under 3D environment conditions on the example of a specific criminal incident-a suspected homicide. The aim of the study was to identify possible circumstances of the events with particular emphasis on the mechanism of death and the involvement of third parties. It was performed a comprehensive 3D reconstruction of the elements of the incident using different sources and forms of evidence, and consequently also different imaging, analysis, and synthesis technologies. The resulting 3D reconstruction and animation of the possible events serve to verify the investigative hypotheses. The paper combines a technical description of the research methodology with a forensic commentary, which ultimately creates an integral synthesis of the medicolegal assessment for trial purposes, while presenting the effectiveness of the research methods used. To sum up, the paper presents an experiment carried out under virtual conditions, impossible to execute under real conditions but critical for trial case analysis.

Exploring the feasibility of smartphone cameras for 3D modelling of bite patterns in forensic dental identification

The field of bitemark analysis involves examining physical alterations in a medium resulting from contact with teeth and other oral structures. Various techniques, such as 2D and 3D imaging, have been developed in recent decades to ensure precise analysis of bitemarks. This study assessed the precision of using a smartphone camera to generate 3D models of bitemark patterns. A 3D model of the bite mark pattern was created using 3Shape TRIOSTM and a smartphone camera combined with monoscopic photogrammetry. The mesiodistal dimensions of the anterior teeth were measured using Rapidform Explorer and OrtogOnBlender, and the collected data were analyzed using IBM® SPSS® Statistics version 23.0. The mean mesiodistal dimension of the anterior teeth, as measured on the 3D model from 3Shape TRIOSTM and smartphone cameras, was found to be 6.95 ± 0.7667 mm and 6.94 ± 0.7639 mm, respectively. Statistical analysis revealed no significant difference between the two measurement methods, p > 0.05. The outcomes derived from this study unequivocally illustrate that a smartphone camera possessing the specific parameters detailed in this study can create a 3D representation of bite patterns with an accuracy level on par with the outputs of a 3D intraoral camera. These findings underscore the promising trajectory of merging smartphone cameras and monoscopic photogrammetry techniques, positioning them as a budget-friendly avenue for 3D bitemark analysis. Notably, the monoscopic photogrammetry methodology assumes substantial significance within forensic odontology due to its capacity for precise 3D reconstructions and the preservation of critical measurement data.

Unmanned Aerial Vehicle (UAV) and Photogrammetric Technic for 3D Tsunamis Safety Modeling in Cilacap, Indonesia

Three-dimensional (3D) modeling of tsunami events is intended to promote tsunami safety. However, the developed 3D modeling methods based on Computational Fluid Dynamics and photorealistic particle visualization have some weaknesses, such as not being similar to the original environment, not measuring the wave’s end point, and low image accuracy. The method for 3D modeling of tsunamis that results from this research can fulfil those weaknesses because it has advantages, such as being able to predict the end point of waves, similar to the original environment, and the height and area of inundation. In addition, the method produces more detailed and sharper spatial data. Modeling in this research is conducted using Agisoft Metashape Professional software to a produce 3D orthomosaic from pictures taken with Unmanned Aerial Vehicle (UAV) technique or drone (photogrammetry), and 3ds max software is used for wave simulation. We take a sample of an area in Cilacap, Indonesia that was impacted by the 2006 southwest coast tsunamis and may be vulnerable to future big megathrust earthquakes and tsunamis. The results could be used to provide several benefits, such as the creation of evacuation routes and the determination of appropriate locations for building shelters.

Multimodal Imagery in Forensic Incident Scene Documentation

Various imaging modalities are evaluated for use in forensic incident (crime or accident) scene documentation. Particular attention is paid to the precision vs. cost tradeoff, accomplished by judiciously combining various 3D scans and photogrammetric reconstructions from 2D photographs. Assumptions are proposed for two complementary software systems: an event scene pilot assisting the on-site staff in their work securing evidence and facilitating their communication with stationary support staff, and an evidence keeper, managing the voluminous and varied database of accumulated imagery, textual notes and physical evidence inventory.

An automatic image-based modelling method applied to forensic infography

This paper presents a new method based on 3D reconstruction from images that demonstrates the utility and integration of close-range photogrammetry and computer vision as an efficient alternative to modelling complex objects and scenarios of forensic infography. The results obtained confirm the validity of the method compared to other existing alternatives as it guarantees the following: (i) flexibility, permitting work with any type of camera (calibrated and non-calibrated, smartphone or tablet) and image (visible, infrared, thermal, etc.); (ii) automation, allowing the reconstruction of three-dimensional scenarios in the absence of manual intervention, and (iii) high quality results, sometimes providing higher resolution than modern laser scanning systems. As a result, each ocular inspection of a crime scene with any camera performed by the scientific police can be transformed into a scaled 3d model.

Application of Kinect gaming sensor in forensic science

Kinect sensor appears as a low-cost option for 3D modeling. This manuscript describes a methodology to test the applicability of Kinect to crime scenes. The methodology includes the comparison versus well-established scanners (Faro and Trimble). The parameters used for the comparison are the quality in the fitting of primitives, a qualitative evaluation of facial data, the data quality for different ranges, and the accuracy in the measurement of different lengths. The results show that the Kinect noise level increases with range, from 5 mm at 1.5 m range to 15 mm at 3 m range. It is considered that for detail measurements the sensor must be placed close to the target. A general measurement of a sample crime scene was analyzed. Errors in length measurements are between 2% and 10% for 3 m range. The measurement range must be limited to c. 3 m.