In Japan, the number of elderly people who go missing has been increasing year by year. A delay in finding a missing person can lead to death. However, there are limits to the early detection that can be achieved through search efforts conducted by volunteers using visual observation. Therefore, there is hope that a method that utilizes information from security cameras and person matching technology can be used to track the whereabouts of missing persons and help with the early detection. In recent years, there has also been interest in person matching technology that utilizes 2D pose estimation. However, there is a problem that the person matching accuracy decreases due to the decrease in the pose estimation accuracy caused by the blocking of body parts due to the shooting angle of the security camera or the person’s clothes. This paper proposes a method to improve the person matching accuracy by focusing on the parts that are susceptible to a decrease in pose estimation accuracy and by masking the pose estimation information. As a result of the evaluation, the average accuracy rate improved by 3.7% with the proposed method compared to the case without masking. In the future, this technology will facilitate the early discovery of missing persons and contribute to the creation of a society where the elderly can live safely and securely.