Securing Venues

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Facilities can mitigate and prevent deaths during an attack by employing target hardening techniques to secure their venues before an attack. Our analysis, which included examining on-location differences between high-casualty and low- or no-casualty attacks, revealed two major types of environments that are especially at risk for high-casualty attacks. Our analysis also revealed three effective actions to mitigate casualties in at-risk environments.

High-Risk Venues

Types of Sites Being Targeted. The figure below shows the number of times different types of locations were targeted in our data set. The dark-blue bars reflect foiled plots, while the light-blue bars reflect executed plots. As shown, educational facilities and "Outdoors, event, or other" were the most frequently targeted locations. (The "outdoors" category includes attacks against on-street locations, outdoor venues, outdoor events, and movie theaters.) There were also comparatively high numbers of plots against houses of worship, government facilities, restaurants and bars, and shopping malls. Using the categories below, we divided the targeted locations into three broad areas:

  • attacks on education (schools, colleges, and universities)
  • attacks on workplaces (health care facilities, military facilities, nonmilitary government buildings, and private buildings) (The first two types of workplaces were typically related to the perpetrator.)
  • attacks targeting crowds in general, for either political or personal reasons (houses of worship; restaurants, bars, or nightclubs; shopping malls, transportation facilities).

Types of Sites Being Targeted

  Foiled Executed
School/College/University 126 69
Outdoors, event, or other 80 103
Private Building 21 44
Non-Military Government Facility 25 8
House of Worship 17 16
Restaurant/Bar/Night Club 7 23
Military Facility 11 9
Multiple 11 9
Transportation Facility 10 6
Shopping Mall or Center 5 11
Healthcare Facility 3 7
Not applicable 10 0

The following figure shows the average number of fatalities per attack by type of location targeted. Houses of worship; shopping malls; restaurants, bars, or nightclubs; military facilities; and attacks occurring across multiple sites ("Multiple" in the figure) had the highest numbers of fatalities (more than four per attack).

Average Number of Fatalities per Attack by Type of Location Targeted

Type of Location Average Fatalities
House of Worship 5.1
Shopping Mall or Center 4.9
Restaurant/Bar/Night Club 4.7
Multiple 4.7
Military Facility 4.2
Private Building 3.7
School/College/University 3.0
Other 2.4
Non-Military Government Facility 1.8
Transportation Facility 1.3
Healthcare Facility 0.7

Site Characteristics

There are two major types of high-risk venues: the constrained box and the constrained labyrinth.

Constrained Box

The constrained box is a venue in which a shooter is able to surprise a large crowd in a single space. The crowd is unable to flee from the line of fire easily because of limited exits and obstacles. Examples of the constrained box are clubs, bars, restaurants, theaters, and houses of worship (large sanctuary spaces).

Constrained Box

A graphic shows an active shooter illustrated as a yellow dot, with a star pattern of green dots around them representing people in line of sight to the shooter.

Lines indicating walls show that some individuals, represented by purple dots, are not in the shooter's line of sight, but that the shooter is between everyone and the only exit, depicted as a door at the bottom of the graphic.

A constrained box has (1) a crowd in a confined space and (2) barriers or doorways that restrict movement within the confined space. The people within the constrained box have a

  • limited ability to exit the confined space because of few or blocked exits
  • limited ability to see the shooter before the shooter has a direct line of fire
  • limited ability to hide from the shooter, which would keep the shooter from having a direct line of fire.

Constrained Labyrinth

The constrained labyrinth is a venue in which a shooter is able to engage a crowd across a series of interconnected spaces. Although the crowd has more options to hide and flee than in a constrained box, escape is still difficult because of limited exits. The shooter can similarly use concealment and site complexity to surprise groups in individual spaces and evade responders for long periods. Examples include schools, office buildings, transit hubs, houses of worship with multiple gathering rooms and offices, and outdoor events and spaces with such constraints as vehicles.

Constrained Labyrinth

A graphic depicts a large number of interconnected rooms. Similar to the "Constrained Box" graphic above, the active shooter is a yellow dot, and can see a star pattern of green dots (depicting individuals in the shooter's line of sight). The warren of rooms blocks many more individuals (represented as purple dots) from the shooter's line of sight, but the primary way in or out remains a single door (depicted at the bottom of the graphic).

A constrained labyrinth has (1) a crowd dispersed across a maze of interconnected spaces and (2) barriers and doorways that restrict movement across the interconnected spaces. The people within the constrained labyrinth have a

  • limited ability to exit the area because of few or blocked exits
  • limited ability to see the shooter before the shooter has a direct line of fire
  • greater ability to hide from the shooter than in the single constrained box, but places to hide are still limited (e.g., people cannot lock doors to close off rooms).

Furthermore, there are many places that the shooter could be within the constrained labyrinth, making the shooter difficult for responders to find.

Types of High-Risk Locations

In this section, we provide more information on where these two major types of high-risk environments come from.

We developed these descriptions of the two types of high-risk environments after reviewing descriptions and articles about the highest-casualty mass shootings in the United States and then performing a qualitative analysis and clustering common characteristics in these attack locations.

The description of the constrained box is based on the following high-casualty mass shootings:

  • Pulse nightclub shooting (which also has aspects of the constrained labyrinth because of barriers between the bar areas, bathrooms, and dressing rooms) (Orlando, Florida)
  • Sutherland Springs church shooting (Sutherland Springs, Texas)
  • Luby's Cafeteria shooting (Killeen, Texas)
  • San Bernardino Inland Regional Center shooting (San Bernardino, California)
  • Binghamton American Civic Association shooting, which took place in a classroom (Binghamton, New York)
  • Aurora movie theater shooting (Aurora, Colorado)
  • Borderline Bar and Grill shooting (Thousand Oaks, California)
  • Las Vegas music festival shooting, in which the perpetrator shot at festivalgoers in the constrained box of the festival area from an elevated distance (Las Vegas, Nevada).

The description of the constrained labyrinth is based on the following:

  • Virginia Tech shooting (Blacksburg, Virginia)
  • Sandy Hook Elementary School shooting (Newtown, Connecticut)
  • El Paso Walmart shooting (with the parking lot, front entrance, and in-store locations effectively being rooms) (El Paso, Texas)
  • Marjory Stoneman Douglas High School shooting (Parkland, Florida)
  • Fort Hood Soldier Readiness Processing center shooting (Fort Hood, Texas)
  • Columbine High School shooting (Columbine, Colorado)
  • Washington Navy Yard shooting (Washington, D.C.)
  • Virginia Beach Municipal Center shooting (Virginia Beach, Virginia)
  • Tree of Life synagogue shooting (Pittsburgh, Pennsylvania)
  • Santa Fe High School shooting (Santa Fe, Texas).

Next Page in the Mitigate Phase

Mitigation Actions