To investigate the pattern of neck injuries and the role of toxicology in cases of hanging and manual/homicidal ligature strangulation in Ireland between 2016 – 2020: A retrospective review and analysis

Abstract

The pattern of neck injuries sustained in fatal cases of external compression to the neck is recorded during Post Mortem Examinations (PME), to assist in the interpretation of the circumstances that led to death. In this study, the PMEs performed for 298 cases of hanging and strangulation occurring between 2016 and 2020 in Ireland were retrospectively reviewed for the purpose of recording and collating the external and internal neck injuries observed during each PME, as well as the toxicology results for each decedent. Statistical analysis was performed to investigate potential novel associations between anthropometric variables pertaining to the decedents and the PME findings in cases of hanging and strangulation, serving to add further data to the existing body of research in this area and to assist in the resolution of future cases of hanging or strangulation where there are conflicting findings. In completing statistical analysis, it was found that there was no discernible association between the occurrences of cartilaginous neck fractures (CNFs) with increasing ligature width. Positive associations between increasing weight and BMI of the decedents were identified, and a significantly positive association between the increasing height of the decedent and the incidence of CNFs were identified. Analysis of the toxicology demonstrated that antipsychotics were implicated most frequently in cases of incomplete and complete hanging associated with CNFs and that opioids were implicated most frequently in cases of manual and ligature strangulation associated with CNFs.

Objective

To record the pattern of neck injuries sustained in retrospective cases of hanging and manual/ligature strangulation and to collate these findings so as to provide scientific evidence to support the interpretation of the findings in future cases of suicidal hanging and homicidal manual/ligature strangulation for the purpose of medicolegal investigation. To analyse the associations between the occurrence of neck fractures and anthropometric variables pertaining to the victims in cases of complete hanging.

Study design

The reports of 298 Post Mortem Examinations (PMEs) performed for cases of hanging and manual/homicidal ligature strangulation between 2016 and 2020 in Ireland were retrospectively reviewed. Pseudoanonymised data sets were recorded for each report, which included the following parameters: neck injuries (soft tissue and cartilaginous), weight, height, BMI and ligature width, toxicology, noose position, ligature material, tongue protrusion, sex and age. Permission for the use of this data was sought from the pathologists and coroners involved in these cases. The data was analysed according to descriptive statistical methods and logistic regression analysis.

Results

Logistic regression analysis was undertaken to examine the associations between unit increases in ligature width and increases in a set of physical characteristics of the decedents (weight, BMI and height) with the occurrence of CNFs. Increasing ligature width was not found to increase the likelihood of a CNF occurring, where the Odds Ratio (OR) for this event occurring was 0.9596. Unit increases in body weight and BMI were found to increase the likelihood of the occurrence of a CNF with ORs of 1.0166 and 1.0607 respectively. Increasing height of the decedent yielded an OR = 4.64, demonstrating that CNFs are significantly more likely to occur with increasing height (CI 95 %: 0.2915, 73.9559).

Conclusions

According to the statistical analysis performed for this study, increasing weight, height and BMI are parameters of the decedents which increase the likelihood of the occurrence of CNFs in cases of complete hanging.