U.S. flag

An official website of the United States government, Department of Justice.

Unobtrusive Suicide Warning System, Final Technical Report, Phase III

NCJ Number
Date Published
September 2012
202 pages
This report describes the methodology and results of the third and final phase of a project that developed a prototype demonstration system that can measure an inmate's heart rate, breathing rate, and general body motion from a non-contact distance, so as to provide custodial facility staff with warning signs of a potential suicide attempt (hanging, asphyxiation) that warrants immediate intervention.
Phase III focused on hardening and integrating the system for long-term testing in an operational setting. Phase I addressed hardware modifications of a version of a commercialized Range Controlled Radar (RCR) that was originally designed as a motion detector for home security systems. Phase II conducted a field demonstration of the prototype system in an actual prison environment and continued the algorithm development in order to increase sensitivity and specificity. This was done to increase detections and reduce false alarms. Phase III involved pre-production engineering and implementation of the hardware and algorithms development in prior program phases and making the system tamper-proof and suicide-proof. The changes included modifying the RCR to match the earlier prototype system, identifying a data acquisition mechanism that could be packaged with the RCR, supplying a long-term power source, and installation in a prison-rated fixture. New software to collect the RCR signals and perform the state and alarm analyses was implemented on a central computer. The RCR sensor, the fundamental component of the system, is available at retail for approximately $50. Cost-effective adoption of the system will depend on assessment of the infrastructure installation costs, which may vary across Federal, State, and local facilities of differing construction. At the completion of this program, a long-term testing in real-world environments is needed to optimize the configurations, settings, and features of the system. 16 figures and appended final technical reports from phases I and II

Date Published: September 1, 2012