Deadly force, also known as lethal force, is the
use of force that is likely to cause
serious bodily injury or
death
Death is the end of life; the irreversible cessation of all biological functions that sustain a living organism. Death eventually and inevitably occurs in all organisms. The remains of a former organism normally begin to decompose sh ...
to another person. In most jurisdictions, the use of deadly force is justified only under conditions of extreme necessity as a
last resort, when all lesser means have failed or cannot reasonably be employed.
Firearm
A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions).
The first firearms originate ...
s,
bladed weapons,
explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An ex ...
s, and
vehicle
A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...
s are among those
weapon
A weapon, arm, or armament is any implement or device that is used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime (e.g., murder), law ...
s the use of which is considered deadly force. The use of
non-traditional weapons in an offensive manner, such as a
baseball bat, sharp pencil, tire iron, or other, may also be considered deadly force.
United Kingdom
The
Criminal Justice and Immigration Act 2008 allows householders to use reasonable force against intruders. In certain circumstances this can be lethal force.
United States law

The
United States Armed Forces
The United States Armed Forces are the Military, military forces of the United States. U.S. United States Code, federal law names six armed forces: the United States Army, Army, United States Marine Corps, Marine Corps, United States Navy, Na ...
defines deadly force as "Force that is likely to cause, or that a person knows or should know would create a substantial risk of causing, death or serious bodily harm or injury.".
[Robert C. Ankony, "Sociological and Criminological Theory: Brief of Theorists, Theories, and Terms," ''CFM Research'', July 2012, page 37.]
In the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
, the use of deadly force by sworn
law enforcement officers is lawful when the officer reasonably believes the subject poses a significant threat of serious bodily injury or death to themselves or others. The use of deadly force by law enforcement is also lawful when used to prevent the escape of a fleeing felon when the officer believes escape would pose a significant threat of serious bodily injury or death to members of the public. Common law allowed officers to use any force necessary to effect a felony arrest, but this was narrowed in the ''
Tennessee v. Garner'' ruling in 1985 when the
U.S. Supreme Court said that "deadly force...may not be used unless necessary to prevent the escape, and the officer has
probable cause to believe that the suspect poses a significant threat of death or serious bodily harm to the officer or others."
In the 1989 ''
Graham v. Connor'' ruling, the Supreme Court expanded its definition to include the "objective reasonableness" standard—not subjective as to what the officer's intent might have been—and it must be judged from the perspective of a reasonable officer at the scene—and its calculus must embody the fact that police officers are often forced to make split-second decisions about the amount of force necessary in a particular situation.
Most
law enforcement agencies
A law enforcement agency (LEA) is any government agency responsible for law enforcement within a specific jurisdiction through the employment and deployment of law enforcement officers and their resources. The most common type of law enforcement ...
establish a
use of force continuum, starting with simple presence through deadly force. With this model, officers attempt to control subjects and situations with the minimum force necessary. Agencies often have policies limiting the force used to be equal or one step higher on the continuum relative to the force they are opposing.
A
civilian's use of deadly force is generally
justified if they reasonably believe that they or another person are in imminent danger of death or serious injury.
Justification and affirmative defenses vary by state and may include certain property crimes, specific crimes against children, or the prevention of sexual assaults.
U.S. law requires an investigation whenever a person causes another person's death, but the mechanism for such investigations can vary by state. The investigation develops evidence regarding the use of deadly physical force for a particular state or jurisdiction. An investigation may be performed by a local or state police agency and also a civilian agency, such as a county prosecutor or State Attorney General.
A report of the findings of such an investigation may be submitted for prosecution and made public.
The US police killing rate is 3.05 police killings per million of
population
Population is a set of humans or other organisms in a given region or area. Governments conduct a census to quantify the resident population size within a given jurisdiction. The term is also applied to non-human animals, microorganisms, and pl ...
. The US police killing rate of Blacks is 5.34 per million; of Hispanics is 2.63 per million; of Whites is 1.87 per million, and of others is 1.5 per million of population. The US police killing rate of Blacks is 2.86 times the US police killing rate of Whites.
US police killing rates compare unfavorably with other jurisdictions.
[Paull, John (2019)]
The Use of Lethal Force by Police in the USA: Mortality Metrics of Race and Disintegration (2015-2019)
Journal of Social and Development Sciences. 5 (4): 30-35
In relation to motor vehicles
In , the
U.S. Supreme Court held that a police officer's attempt to terminate a dangerous high-speed car chase that threatened the lives of innocent bystanders did not violate the
Fourth Amendment, even when it places the fleeing
motorist at risk of serious bodily injury or death. In the ''Harris'' case, Officer Scott
applied his police car's push bumper to the rear of the suspect's vehicle, causing the
suspect
In law enforcement jargon, a suspect is a known person accused or suspected of committing a crime. Police and reporters in the United States often use the word suspect as a jargon when referring to the perpetrator of the offense (perp in dated U. ...
vehicle to lose control and crash, resulting in the fleeing suspect being paralyzed from the waist down.
Traditionally, intentional contact between vehicles has been characterized as unlawful deadly force, though some U.S. federal appellate cases have mitigated this precedent. In
,
the Eleventh Circuit Court of Appeals ruled that, although fatalities may result from intentional collisions between automobiles, such fatalities are infrequent and therefore unlawful deadly force should not be presumed to be the level of force applied in such incidents; the Adams case was subsequently called into question by
, which in turn was reversed by the U.S. Supreme Court in the ''Scott v. Harris'' case discussed above; the extent to which ''Adams'' can continue to be relied on is uncertain. In the ''Adams'' case, the officer rammed the suspect's vehicle.
In
, the Seventh Circuit Court of Appeals recognized this principle but added that collisions between automobiles and motorcycles frequently lead to the death of the motorcyclist, and therefore a presumption that unlawful deadly force was used in such intentional collisions is more appropriate. In the ''Donovan'' case, the suspect lost control of his motorcycle and became airborne, crashing into the officer's vehicle, which was parked as part of an intercepting roadblock.
Situational threats
There are two main types of critical threats a suspect may pose: 1) escape and 2) physical harm. The latter threat involves a threat of violence, bodily harm, and/or death. If the suspect threatens to harm civilians and/or officers, then those officers must act to protect themselves and the public. In such a scenario, the perception of the officer(s) is critical. If there is a realistically perceived threat (i.e., the suspect is putting lives in danger), then officers may take the life of the suspect in order to protect themselves and the public. However, these situations can become complicated if the threat is not perceived as 'genuine', or if the suspect is in a location in which the use of deadly force to subdue the suspect may place other innocent bystander lives in danger.
[ Alpert, Geoffrey P., Smith, William C., (1994) How Reasonable is the Reasonable Man. ''Journal of Criminal Law and Criminology''. 85(2), 481-501. ]
See also
*
Fleeing felon rule
*
Non-lethal weapon
*
Peelian principles
*''
Plummer v. State''
*''
Tennessee v. Garner''
*''
Graham v. Connor''
*
Proactive policing
*
Rules of engagement
*
Self-defense
Self-defense (self-defence primarily in Commonwealth English) is a countermeasure that involves defending the health and well-being of oneself from harm. The use of the right of self-defense as a legal justification for the use of Force (law), ...
*
Stand-your-ground law
References
{{DEFAULTSORT:Deadly Force
Law enforcement agency powers
Violence
Self-defense
Law enforcement terminology
Law enforcement use of force