Suicidal hanging with complete decapitation: A forensic case report with review of biomechanics.

Decapitation resulting from hanging is an infrequent phenomenon, often influenced by multiple biomechanical factors. We report a case of a 72-year-old male who committed suicide by hanging, leading to complete decapitation. The drop height was approximately 10.668 m, with a static nylon rope of 9 mm thickness used as ligature material. Autopsy findings showed complete severance at the cervical spine level, primarily at the junction of C4/C5 with an additional anterior hemi-transection at the C6/C7 junction. Calculations revealed axial and radial forces acting at the neck to be 534.1 N and 3354.15 N, respectively, which were found within the range of required forces described in the literature. Biomechanical analysis indicated the significant roles played by body weight, drop height, ligature material, and anatomical vulnerability due to advanced age. This report emphasizes the necessity for further research into biomechanics of different ligature materials and how aging affects the mechanical strength of cervical soft tissues, influencing susceptibility to cervical injuries and decapitation in hanging.