If that’s what they’re doing…they’re doing a sh*tty job of that too.
Just thinking out loud here, if authorities were searching for a dirty bomb with drones, they would use radiation sensors on drones flying systematic grid patterns, supported by ground teams for verification. They'd prioritize potential hiding spots like abandoned areas or high-traffic zones, rely on intelligence tips, and integrate other technologies like satellite imaging and canine units.
However, this scenario seems unlikely without specific intelligence, as dirty bombs are hard to detect and shielded containers could block radiation.