The effectiveness of surveillance technology for the prevention of suicides in public spaces: a systematic review

BackgroundThe use of surveillance technologies 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. MethodsWe conducted systematic searches between 1990 up to 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. 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). Study results were synthesised using narrative and tables. ResultsThe searches identified 2,647 items, with 15 studies meeting the eligibility criteria. Just one study provided clear evidence of a reduction in suicides at a site (a bridge) after installation of a "smart" surveillance system, but its use of tension-wire sensors also restricted ease of physical access. The presence of CCTV cameras was associated with lower rates of suicide at local rail stations in one study, but this was not a significant factor in two other studies of metro stations. Two studies observed an increase in interventions following the installation of smart surveillance technologies (SSTs) on bridges, but with no change in suicides rates. Three studies indicated that SSTs with audible deterrents may reduce trespass to dangerous sites, but their relevance to suicide prevention is unclear. ConclusionsThe 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. Key messagesO_ST_ABSWhat is already known on this topicC_ST_ABSO_LIIt is thought that surveillance technologies may aid suicide prevention efforts at public locations by increasing opportunity for human intervention. However, it is unclear whether they are effective at preventing suicides. C_LI What this study addsO_LIur systematic review found 15 studies that examined the effectiveness of installing surveillance technologies at preventing suicides or trespass at public locations. C_LIO_LIverall, the evidence of surveillance technologies helping to prevent suicide was limited. C_LIO_LIsome locations the installation of surveillance technologies was associated with an increase in numbers of interventions or police call outs, but not a decrease in deaths. C_LIO_LIuse of audible deterrents may be effective for preventing trespass, however, to date there remains no evidence that they will help to prevent suicides. C_LI How this study might affect research, practice or policyO_LIThe findings highlight critical gaps in the current evidence, particularly in regard to the use of "smart" or "intelligent" surveillance technologies. C_LIO_LIFurther research is also needed to understand the impact of processes surrounding surveillance technologies on their effectiveness (e.g., rescue response times). C_LI