Fire Scene Investigation with the Leica RTC360 laser scanner
Why Dubai Police uses state-of-the-art 3D technology for documentation of incidents
Examination and documentation of the scene is a vital phase in any reported fire or explosion incident. Type and scope of an investigation vary from case to case, that’s why for the investigators it is crucial to follow standardised procedures and rely on best-in-class, proven and fast-working equipment.
In the processing of physical evidence on a scene, there are 4 basic, but important steps to be followed by every investigator:
- Identify, Collect, and Preserve Evidence
- Prevent Contamination
- Package and Transport Evidence
- Establish and Maintain the Chain of Custody
During a forensic investigation of a fire or arson scene, the proper preservation of the evidence is crucial. Thus, there are precise site measurements required. The result can be a multi-dimensional reproduction of the collected evidence. In this article, we will talk about step one, especially the digital preservation of evidence of a fire or arson scene.
It has been a known challenge to forensic specialists to capture a wide range of rather complex, post-incident features of structural damage of a building and debris thoroughly, given the short time frame for the collection and the complexities associated with safety on-site. Likewise, hazardous environments and the nature of a fire or arson scene might be of an additional challenge for the investigators. That’s why the use of terrestrial laser scanning technologies (fast and accurate scanning from a safe distance) has been of interest to the wider forensic engineering community.
Conventional methods, including the image capturing using SLR cameras or the manual collection of evidence on the scene, might become hazardous and laborious as well as highly contagious due to some limiting factors such as weather, light, radiation, and other conditions.
For example, in post-explosion investigations, it is crucial to study the impact of shock waves, the severity of the damage, and the directions of the falling debris. Without accurate documentation of the scene, these might be difficult to observe in later investigative stages, along with the chance of missing evidence becoming much higher. In large-scale accidents, even the most experienced investigators are bound to mistakes and can’t fully ensure, that they have all the observations well-documented. They possibly could miss measuring some of the important details of the incident, whilst the site is being cleaned and reconstructed by the other parties involved.
3D laser scanning can be utilized to document fire or arson incident scenes more inclusively, compared to traditional tools and methods of scene mapping and analysis. 3D laser scanners, like the Leica RTC360, can easily capture fine details and spatial relationships with speed, comprehensiveness and 0.1-inch accuracy, regardless of environmental conditions and site range. Forensic software such as Leica Map360 can integrate collected scan data directly with for example CCTV footage, images, and other relevant documents into models for analysis and hypothesis. Results of the data analysis can be easily accessed from computers in the crime/fire laboratory or anywhere else, providing an easy and accessible way to revert to the details when needed. Event weeks or months after the fire happened.
Major (Dr.) Mohammad A. Alqassim from the Dubai Police leads a team of forensic experts experienced in the investigation of fires, the analysis of evidence gathered, or the use in the criminal justice system of information produced by the investigation. Major Alqassim and his team have been utilising various portable and stage-mounted 3D scanners for case investigations for many years aiming to implement new technologies in his team’s daily work to gather best results.
One of the main challenges in Dubai is challenging site conditions including the environment e.g. high temperatures, dusty/smoky surroundings, ultra-high humidity. These may deter the investigators from completing their work as intended. Dubai Police was looking for a device being able to cope with challenging surroundings and still deliver results, they can rely on with capabilities to work in rains/water splashes and extended temperature ranges.
During the extinguishing of the fire, movements of the firefighters and their patrols must not be restricted to facilitate on-time accurate evidence positioning to avoid further delay in investigation. For the investigators, every delay in the capture of the site may deter much of the information needed. The site may be altered from its original situation. In this case, the biggest challenge is to fast obtain as clean as possible data (point clouds) using the 3D laser scanner. After completing the scans on-site, the registering and tagging the information captured, happens in the office and is performed by the technical expert to visualise the scan results.
The Leica RTC360 3D laser scanner was launched in mid-2018 to address these challenges with its new features including the VIS technology (Visual Inertial System), enclosed mirror, and full-time HDR photography. Auto-calibration (“check and adjust”) features of the device ensure consistent accurate measurements. The newly added tagging feature allows for the integration of evidence photography, videography and witness testimony in 3D scans using software called Leica Cyclone FIELD 360. The double scan possibility in the RTC360 laser scanner is one of the key features to capture which enables investigators, to capture the “noiseless” data without the moving people or objects around the scene. Finally, with the launch of RTC360 laser scanner all the investigator’s requirements and applications were addressed.
Major (Dr) Mohammad A. Alqassim and his team along with Dr Satendra Kumar, public safety and a forensic expert from Leica Geosystems, decided to examine the implementation of this new technology to capture incidents (both on-site and in the office) to deliver audio/visual scene reconstruction and reporting. From early 2020, the forensic engineering team at the Dubai Police has been utilising the RTC360 to capture, map and analyse reported fire incidents. The RTC360 reduces the time required on the scene to nearly half, compared to previous generation scanners and mapping tools to capture any scene with HDR. Now, live 3D data visualisation and scanner tracking with the help of VIS technology enabled investigators to capture scenes with more confidence and ease. VIS also enabled investigators to have auto-registered data onsite. Advanced image and video tagging, notations and onsite mobile app-based data registration in the software Cyclone FIELD 360 have save valuable time in the office for integration of point clouds, evidence images, tags and analysis in mainframe databases of the investigation department.
The RTC360 laser scanner ensures, that more investigations are successfully concluded through the proper identification, collection, and examination of all relevant forensic evidence. The laser scanner has proven to be the best-in-class tool used in scene documentation and analysis for forensic engineers at the Dubai Police, who’s dedication in improving the procedures for fire/arson scene investigation is truly exemplary
About Dr. Mohammad A. Alqassim
About Dr. Satendra Kumar