Oklahoma City bombing in the context of Federal Assault Weapons Ban

A car bomb, bus bomb, van bomb, lorry bomb, or truck bomb, also known as a vehicle-borne improvised explosive device (VBIED), is an improvised explosive device designed to be detonated in an automobile or other vehicles.

Car bombs can be roughly divided into two main categories: those used primarily to kill the occupants of the vehicle (often as an assassination) and those used as a means to kill, injure or damage people and buildings outside the vehicle. The latter type may be parked (the vehicle disguising the bomb and allowing the bomber to get away), or the vehicle might be used to deliver the bomb (often as part of a suicide bombing).

The Federal Emergency Management Agency (FEMA) is an agency of the United States Department of Homeland Security (DHS), initially created under President Jimmy Carter by Presidential Reorganization Plan No. 3 of 1978 and implemented by two Executive Orders on April 1, 1979. The agency's primary purpose is to coordinate the response to a disaster that has occurred in the United States and that overwhelms the resources of local and state authorities. The governor of the state in which the disaster occurs must declare a state of emergency and formally request from the president that FEMA and the federal government respond to the disaster. The only exception to the state's gubernatorial declaration requirement occurs when an emergency or disaster takes place on federal property or to a federal asset—for example, the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma, or the Space Shuttle Columbia in the 2003 return-flight disaster.

While on-the-ground support of disaster recovery efforts is a major part of FEMA's charter, the agency provides state and local governments with experts in specialized fields, funding for rebuilding efforts, and relief funds for infrastructure development by directing individuals to access low-interest loans, in conjunction with the Small Business Administration. In addition to this, FEMA provides funds for response personnel training throughout the United States and funds for non-federal entities to provide housing and services for migrants released from Department of Homeland Security custody.

Domestic terrorism or homegrown terrorism is a form of terrorism in which victims "within a country are targeted by a perpetrator with the same citizenship" as the victims. There are various different definitions of terrorism, with no universal agreement about it.

Unlike domestic terrorism, state terrorism is that perpetrated by nation states, but is not considered such by the state conducting it, making legality a grey area.

A mass casualty incident (often shortened to MCI) describes an incident in which emergency medical services resources, such as personnel and equipment, are overwhelmed by the number and severity of casualties. For example, an incident where a two-person crew is responding to a motor vehicle collision with three severely injured people could be considered a mass casualty incident. The general public more commonly recognizes events such as building collapses, train and bus collisions, plane crashes, earthquakes and other large-scale emergencies as mass casualty incidents. Events such as the Oklahoma City bombing in 1995, the September 11 attacks in 2001, and the Boston Marathon bombing in 2013 are well-publicized examples of mass casualty incidents. The most common types of MCIs are generally caused by terrorism, mass-transportation accidents, fires or natural disasters. A multiple casualty incident is one in which there are multiple casualties. The key difference from a mass casualty incident is that in a multiple casualty incident the resources available are sufficient to manage the needs of the victims. The issue of resource availability is therefore critical to the understanding of these concepts. One crosses over from a multiple to a mass casualty incident when resources are exceeded and the systems are overwhelmed.

John Foster "Chip" Berlet (/bɜːrˈleɪ/; born November 22, 1949) is an American investigative journalist, research analyst, photojournalist, scholar, and activist specializing in the study of extreme right-wing movements in the United States. He also studies the spread of conspiracy theories. Since the 1995 Oklahoma City bombing, Berlet has regularly appeared in the media to discuss extremist news stories. He was a senior analyst at Political Research Associates (PRA), a non-profit group that tracks right-wing networks.

Berlet, a paralegal, was a vice-president of the National Lawyers Guild. He has served on the advisory board of the Center for Millennial Studies at Boston University, and for over 20 years was on the board of the Defending Dissent Foundation. In 1982, he was a Mencken Awards finalist in the best news story category for "War on Drugs: The Strange Story of Lyndon LaRouche", which was published in High Times. He served on the advisory board of the Campaign to Defend the Constitution.

The Alfred P. Murrah Federal Building was a United States federal government complex located at 200 N.W. 5th Street in downtown Oklahoma City, Oklahoma. On April 19, 1995, the building was the target of the Oklahoma City bombing by Timothy McVeigh and Terry Nichols, which ultimately killed 168 people and injured 684 others. A third of the building collapsed seconds after the truck bomb detonated. The remains were demolished a month after the attack, and the Oklahoma City National Memorial was built on the site.