Prisoner suicide has been one of the leading causes of death in correctional facilities. In particular, since hanging is the most common suicide method, various systems have been proposed to detect and prevent hanging attempts. This letter presents the preliminary results of applying 3-D image recognition techniques to detect a partial suspension hanging attempt. This is the most frequently occurring method of hanging in prison settings, but is difficult to recognize using conventional methods. By using a 3-D camera and random forest, the experimental results show that the proposed detection algorithm can detect hanging suicide attempts with more than 95% accuracy.