# Comparative Analysis of LiDAR and Photogrammetry for 3D Crime Scene Reconstruction
## 2 Related Work
### Applications of LiDAR in Crime Scene Reconstruction
Furthermore, differences between indoor and outdoor scenes, as well as scene size, do impact this choice. LiDAR technology was highlighted in outdoor crime scene scenarios, where its usage can be compared to other sensory tools, such as aerial photogrammetry. Various crime scene documentation techniques were examined in the study by [PERSON] et al. [7], including LiDAR scanners and drone-based photogrammetry. The study showed how these scanners captured a scene in five minutes with one user. This time-saving advantage is crucial compared to methods involving teamwork. However, the researchers also identify challenges, including the need for training, the legal implications, and barriers when implementing such advanced technologies. In the study by [PERSON] et al. [8], Unmanned Aerial Vehicles (UAVs) were utilized to document crime scenes. Furthermore, an evaluation of 3D reconstruction software was introduced in their research, such as Pix4D [22] and Agisoft Metashape. The study recommends using LiDAR and photogrammetry technology to enhance the accuracy and detail of crime scene documentation. Another study on drones with LiDAR for crime scene reconstruction was performed by [PERSON] et al. [23]. According to the survey, drones with high-resolution cameras can capture and record crime scenes from different angles, resulting in enhanced documentation. According to the researchers, innovative technologies must be constantly developed to improve criminal investigation. The research by [PERSON] et al. [24] investigated the challenges of using LIDAR scanning with virtual reality (VR) for crime scene documentation. The results showed that these technologies efficiently enhanced crime scene examination since human eyes often fail to detect small details in a crime scene. In their research, [PERSON] and [PERSON] [9] examined the use of Recon-3D, an app with Apple's LiDAR sensor for documenting bullet trajectories. It compared Recon-3D (Recon-3D Inc., Woodbridge, ON, Canada) to the Faro Focus S350 laser scanner (FARO, Lake Mary, FL, USA), and its results showed that Recon-3D's accuracy and repeatability were similar. While the Recon-3D app is user-friendly and efficient, it may occasionally crash during high-resolution scans. However, due to the high sensitivity of the forensic field, where no mistakes are accepted, it is recommended that further validation and exploration of the tested Recon-3D application be conducted. A study focusing on documenting bullet trajectories at crime scenes was performed by [PERSON] et al. [10], which explored the BLK2 GO LiDAR scanner (Lecia Geosystems, Heerbrugg, Switzerland) capabilities. The key findings suggest that, although the handheld scanner offers mobility in addition to ease of use, it falls short in data quality and precision, especially when dealing with evidence like bullets. Yet, it can be suitable for cases in which high accuracy is unnecessary, such as reconstructing general crime scenes [10]. [PERSON] et al. 's research [11] enhances the understanding of integrating innovative technologies like Apple LiDAR using the Recon-3D app in forensic documentation. The study reveals that these technologies can achieve centimeter-level accuracy in reconstructing 3D crash scenes. However, it also highlights potential inaccuracies due to environmental factors and manual measurement errors. These insights are vital for forensic professionals considering adopting advanced technological solutions in scene reconstruction. The study by [PERSON] et al. [12] evaluated the built-in LiDAR sensor of the iPad Pro for its applicability in rapid 3D mapping. Their preliminary analysis reveals that the sensor shows promise for quick surveying tasks due to its affordability plus portability compared to traditional surveying tools. The study highlights the sensor's reliable data collection and rapid processing capability. In the study by [PERSON] et al. [13], the authors evaluate the application of iPhone LiDAR using the Recon-3D app for bloodstain pattern analysis (BPA).