The first gait-based person-verification system that can analyze the gait for forensic science is presented. There are many security cameras set in many places, and gait image sequences can be extracted from the images taken by the cameras. The gait can provide information for identity determination in forensic science; however, the limitation of gait-based person authentication is that the analysis of gait features is a difficult task for non-specialists of gait person authentication. Our system allows non-specialists to analyze gait images taken in different circumstances, and can provide useful information for criminal investigations. We performed evaluation experiments to evaluate the usability of the constructed system. In the experiments, nine participants used the system to analyze gait features. The experimental results show that novices can use the constructed system correctly and obtain reasonable results.