By John S. Hollywood, Keith Gierlack, Pauline Moore, Thomas Edward Goode, Henry H. Willis, Devon Hill, Rahim Ali, Annie Brothers, Ryan Bauer, Jonathan Tran

The U.S. Department of Homeland Security requires research and development to assess methods for reducing the propensity and loss of life from attacks on soft targets and crowded places (ST-CPs). Researchers conducted a comprehensive landscape assessment of the threat to ST-CPs and corresponding security measures to identify needs for improvement, and they recommended research and investment priorities for addressing those needs. 

The number of attack plots is broadly aligned with regional population counts, except that there were more plots in New York City and Washington, D.C. The most-common motivations for ST-CP attacks have been personal, followed by terrorist and racial and ethnic extremist motivations. The ST-CP locations targeted have been diverse and often directly accessible. Education and private buildings (workplaces) are the most–frequently targeted types of ST-CPs. In general, locations in which a would-be attacker had ready access to a dense crowd on scene had the highest average lethality (close to six deaths, on average, as compared with fewer than three when there was not a dense crowd present). Not surprisingly, locations that typically have large crowds without controlled entries, such as houses of worship, shopping malls, restaurants, bars, and nightclubs, had the highest average lethality.

RAND Corporation, Mar 27, 2024, 148 pages