An experimental study on the macroscopic findings of ligature marks using a murine model

Macroscopic findings of ligature marks are mainly affected by the characteristics of the ligature, the severity of external forces acting on the ligature, and the period that the neck has been pressed by the ligature. Therefore, the appearances of ligature marks formed by ligatures with the same characteristics differ depending on 2 factors: force and time. To examine which of these factors contributes more significantly to the macroscopic findings of ligature marks, a semiquantitative and experimental study using a murine model was performed. We experimentally made artificial ligature marks by hanging different sized weights using a vinyl band on dehaired legs of rats for different periods, both intravitally and postmortemly.After weights of 1, 3, and 6 kg with vinyl bands were hung on the legs of rats for 0 to 24 hours, the depths of ligature marks were semiquantitatively evaluated in 4 grades. Macroscopic examination and statistical analysis revealed that the appearance of ligature marks is not affected by whether they are formed intravitally or postmortemly but that it is equally affected by the severity of force and the duration of force application. We believe that the results of this study will be helpful to determine the characteristics of ligature and the period of hanging or strangulation time in the practice of forensic medicine.