In this episode of the Voices from DARPA podcast, Mark Wrobel, a program manager since 2019 in the agency’s Defense Sciences Office (DSO), chronicles progress in the SIGMA+ program and its potential near-term relevance to monitoring the environment for SARS-CoV-2, the virus that causes COVID-19. The now-completed predecessor program, SIGMA, delivered a sensor and analysis system for detecting imminent nuclear and radiological threats in complex settings like cities, stadiums, and travel hubs. That system has been transitioning into deployments. The charge of the SIGMA+ program is to expand the threat-detection system’s abilities to include an extensive range of chemical, explosive, and biological agents. To avoid costly false alarms and potentially lethal false negatives (missed detections), the technology must be able to reliably discern actual threats from the myriad benign nuclear, radiological, chemical, and biological signals that typically are present in any given location. As Wrobel puts it, “We are trying to move detection to the left of boom.”