Diagnostic pitfalls in zip tie ligature strangulation: Findings from a 16-case series and literature review

This study describes 16 deaths from Alberta, Canada, caused by ligature strangulation using self-locking zip tie(s), also known as cable ties. All decedents were male, and all ligatures were horizontally oriented. The manner of death was classified as suicide in 15 cases and undetermined in one. Notably, one quarter of cases lacked petechiae, explained by the highly constrictive nature of zip ties and their ratchet locking mechanism. In half of the cases, neck compression resulted from a single ligature formed by one heavy-duty zip tie (6 cases) or several smaller zip ties interconnected to create one ligature (2 cases). The remaining half of the cases involved multiple zip tie ligatures. Most cases (14/16) demonstrated congestion of the head and neck above the ligature mark, occasionally accompanied by ear or nose bleeding. Review of previously published cases revealed similar findings, except for one reported double homicide involving an adult female and her child, a vulnerable population as further corroborated by several news stories. This study emphasizes the importance of recognizing the unique properties of zip ties, particularly their ratchet mechanism, when evaluating ligature strangulation. Without such awareness, the absence of petechiae or congestion may lead to diagnostic uncertainty and the mistaken assumption that neck compression did not contribute to death. One case involving an elderly male showed neither congestion nor petechiae, raising the possibility of reflex cardiac arrest triggered by carotid sinus stimulation.