Police officers often must work alone in clearing operations, a procedure that involves surveying a building for threats and appropriately responding. A partnership between drone swarms and officers has potential to increase the safety of officers and civilians during these high-stress operations and reduce the risk of harm from hostile persons. This two part study examines aspects of trust, situational awareness, mental demand, performance, and human-robot interaction during law enforcement building clearing operations using either a single drone or a drone swarm. Results indicate that single drone use can increase time for operation, but accuracy and safety of clearing is enhanced. Single drone use saw increased situational awareness, a decrease in number of targets missed, and a moderate level of trust. For drone swarms, results indicate significant differences in mental workload from swarm data feeds compared to single drone feeds but no substantial difference in accuracy of finding targets.