Effectiveness of surveillance technology for the prevention of suicides in public spaces: a systematic review.

Objective: The use of surveillance technologies (eg, security cameras, motion sensors, video analytics) has been recommended for supporting suicide prevention efforts in public spaces. We sought to identify and synthesise the current evidence on the impact of surveillance technologies deployed in such environments on suicide and related outcomes. Design: Systematic review without meta-analysis. Data sources: We conducted systematic searches between 1990 and August 2025 on the following databases: PsycINFO, MEDLINE, CINAHL, Computer Source, Ovid, SPP, Web of Science, PTSDpubs, CENTRAL, ACM DL and IEEE Explore. Our searches also extended to grey literature from relevant websites. Eligibility criteria: Studies were included if they assessed the deployment of surveillance technology at a public location on suicide-related outcomes (including suicides, suicide attempts, rescue interventions and trespass events). Data extraction and synthesis: Two reviewers independently screened studies and extracted data. Study results were synthesised using narrative and tables, and the quality of studies was assessed using the Mixed Methods Appraisal Tool. Results: The searches identified 3039 items, with 15 studies meeting the eligibility criteria. Just one study provided clear evidence of a reduction in suicides (IRR=0.37, 95% CI 0.26 to 0.54) following the installation of a 'smart' surveillance system on a bridge, but its use of tension-wire sensors also restricted ease of physical access. The presence of closed-circuit television cameras was associated with a 7% reduction in rates of suicide at local rail stations in one study (IRR=0.93, 95% CI 0.88 to 0.98), but the presence of cameras was not a significant factor in two metro station studies. Additionally, two studies observed an increase in interventions (eg, rescue responses) following the installation of smart surveillance technologies on bridges (140% and 520% increases, respectively), but saw no change in suicide rates. Three studies indicated that smart surveillance technologies with audible deterrents may reduce trespass to dangerous sites, but their relevance to suicide prevention is unclear. Conclusions: The current evidence base to support the use of surveillance technologies for preventing suicides is limited. There is a clear need for further evaluations of surveillance-based interventions, including their implementation, associated measures and impacts to inform development of effective suicide prevention initiatives.