Funds are required to develop, test and validate a low-cost portable, suitable for setup by two officers, system for detection, echo-location and weapon type classification of firearm discharges in outdoor and indoor environments. The resulting sensor suite will be suitable for securing a typical public event involving hundreds of people. This system will be comprised of modified hardware and software from PNNL's Acoustic Gunshot Detection Technology for confined spaces (USPTO 10089845B2), which is capable of detection and weapon classification, along with time-stamping, recording events and alerting. PNNL's acoustic gunshot detector for confined spaces has been licensed by three commercial entities, one of which already has demonstrated and deployed a full solution in schools across the US, which includes the complete response and communication framework necessary to inform law enforcement and first responders. See, for instance, the EAGL Gunshot Detection and Lockdown System. The development of the portable system will leverage these existing response and communication frameworks providing instantaneous information of a firearm discharge simultaneously to law enforcement and first responders. Appropriate communication methods and protocols will be built into the portable detection system to enable a 'plug and play" configurability of the flexible network of sensors. This prototype and development user interface software will also be suitable for further development and integration into additional commercial First Responder alert systems, which will include outputs for CAD and CAMEO systems as well as other parameters defined by commercial partner. Development will be performed in collaboration with the Kennewick Police Department as we collaborated with this force in development and testing of the Acoustic Gunshot Detection Technology mentioned above (Luzi, Gonzalez, et al. Acoustic firearm discharge detection and classification in an enclosed environment, Journal of the Acoustical Society of America 139(5) 2016, pg. 2723-2731.). During preliminary prototype testing all system components will be deployed and operated by members of the Kennewick Police Force and feedback on design incorporated into the final engineering prototype. An engineering prototype technology transfer package comprised of technical drawings, electronic circuit specifications, and analysis software source code will be produced along with validation data for a selected set of scenarios.