Evaluating the use of smartphone measurement applications for crime scene documentation

As smartphone technology continues to evolve, it begs the question as to whether or not smartphones could be used by crime scene investigators. Crime scene documentation is a time-consuming task when using a standard tape measure compared to advanced techniques (such as 3D scanners). However, these advanced techniques are expensive and take time to set up. Measurement applications could potentially serve as an affordable and sufficient alternative. Therefore, it’s important to understand how accurate these applications are as well as how well they work for measuring crime scenes and forensic evidence. Eleven measurement applications were downloaded (onto an Apple iPhone XR) and evaluated and then narrowed down to four applications to be used in this study. Several parameters were assessed in all eleven applications. Factors such as tools available, effective maximum distance, ease of use, and accuracy were tested. The applications that best met all criteria were used for this study. First, the applications were used to measure several known dimensions such as a ruler, then they were used to measure room dimensions, outdoor scenes, footwear impressions, and bloodstains. Accuracy was assessed by comparing the results from the applications to the measurements made from a standard tape measure or ruler. Standard deviation of all measurements was calculated and compared against one another. Feasibility was evaluated by recording the amount of time that it took to conduct the measurements and comparing the times to one another. Adaptability to various environments was also factored in when evaluating feasibility. Overall, the applications Tape Measure and MagicPlan were found to be the most accurate and feasible applications to use for crime scene measurements. Moasure was found to be the least efficient and precise application in this study. Measure, Moasure, MagicPlan, and Tape Measure serve as an affordable, fast, and easy presumptive tool for crime scene documentation. In the future, these applications could be used to document crime scenes, and could assist particular agencies with insufficient monetary resources. While the applications selected (Measure, Moasure, MagicPlan, and Tape Measure) proved to be accurate, additional tests should be conducted before being implemented exclusively by investigators. With continual progression in modern technology, substantial improvements are anticipated that encompass these smartphone applications, which will increase reliability as it relates to forensics