Deadly force, also known as lethal force, is physical force applied by one person to another that has the potential to cause serious bodily injury or death. Typical examples of deadly force include law enforcement using a deadly weapon to subdue the perpetrator of a crime. Or the police might fire a gun in order to stop a perpetrator from fleeing the police after committing a violent felony.

The use of deadly force must be justified by the circumstances that exist at the time the force is used. Generally, it can be used in extreme circumstances when it is necessary and when lesser means of applying force are inadequate or unavailable.

What Are Deadly Force Laws?

Of course, deadly force can be used by both law enforcement officers and civilians. There are laws that define the circumstances in which the use of deadly force is legal. The Federal Bureau of Investigations (FBI) has a policy for the use of deadly force that sets the standard for officers of the FBI.

Other law enforcement agencies have their own policies regarding the use of lethal force. They may or may not be modeled on the FBI policy. For example, in the state of Connecticut, a state statute sets the standard for the use of deadly physical force by law enforcement in that state. In Connecticut, the use of lethal force is allowed when an officer reasonably believes it is necessary to:

  • Defend themselves or another person from the use of deadly physical force by a assailant;
  • To effect the arrest or prevent the escape of a person whom the officer reasonably believes has committed or attempted to commit a felony involving the infliction or threat of serious physical injury. In addition, before using the force, if possible, the officer must give a warning of their intent to use deadly physical force.

Connecticut law requires the state’s Division of Criminal Justice to investigate any occasion on which a law enforcement officer on duty uses deadly physical force that causes someone’s death. The investigation must determine whether the officer’s use of deadly physical force met the standards of Connecticut’s statute. A report must be submitted to the chief state’s attorney of Connecticut.

Connecticut is not alone in requiring an investigation when a law enforcement officer causes someone’s death. It is standard practice for an investigation to follow a death caused by a law enforcement officer.

When Can Law Enforcement Use Deadly Force?

Whether the use of lethal force is legal in any given situation depends on the law and policies that apply to a given law enforcement agency and the state in which it operates.

FBI policy authorizes federal FBI agents to use deadly force in the following circumstances:

  • To stop a perpetrator from putting other people’s lives in danger by using explosives;
  • In self-defense if there is an immediate danger to the life of either the officer or an innocent bystander;
  • In order to subdue a perpetrator who is in possession of explosives;
  • To prevent sabotage, theft, or a perpetrator who is trying to control a site that contains nuclear material.

Before deadly force is used, an FBI agent must verbally warn a suspect to stop.

In the state of New York, when used, force should be only that which is objectively reasonable given the circumstances perceived by the officer at the time of the event. The law in the state of New York allows the police to use force when an officer reasonably believes that it is necessary to effect a lawful arrest or detention, prevent the escape of a person from custody, or in defense of one’s self or another person.

Whether any particular use of force is reasonable should be judged from the perspective of a reasonable officer on the scene.

Factors that may be considered when determining the reasonableness of force include:

  • The severity of the crime or circumstance;
  • The level of threat or resistance posed by the suspect;
  • How immediate the threat is, whether it is imminent or can be avoided;
  • The potential for injury to citizens, officers, and suspects in the area;
  • Whether the suspect has attempted to escape;
  • Whether there is a risk of an escape attempt;
  • The knowledge, training, and experience of the officer who is going to apply the force;
  • Considerations such as the age, size, relative strength, skill level, injury or exhaustion of the players involved;
  • The number of officers and subjects involved in the confrontation;
  • Other features of the situation, e.g. the weather, or the presence or absence of exigent circumstances.

Can Non-Officers Use Deadly Force?

Whether a person who is not an officer of law enforcement can use deadly force is an issue of state law, and state law varies on this issue. Generally, the average person can use deadly force only in very limited circumstances and would want to do so only when absolutely necessary to protect life and limb. In all states, a person can use deadly force to defend against death, serious bodily injury, rape or kidnapping. Some states allow deadly force to defend against a robbery, burglary or other serious felony offense.

Use of lethal force to defend oneself or another would be legal as long as the person’s fear is reasonable and the danger is imminent. Serious bodily injury would include something on the scale of broken bones.

Some states impose a “duty to retreat” before the use of lethal force is authorized. In states with a duty to retreat, even a person who is defending against an unlawful attack may not use deadly force if it is possible to instead avoid the danger with complete safety by retreating.

A stand-your-ground law, also referred to as “line in the sand” or “no duty to retreat” law, eliminates the duty to retreat before using deadly force in self-defense. However, a person does not have a duty to retreat only if they are lawfully present in a place in which they are attacked.

Even in states that prescribe a duty-to-retreat, there is the “castle doctrine“, which relieves people of their duty to retreat when they are attacked in their homes. Some states relieve people of the duty to retreat in their vehicles or workplaces as well as in their homes.

The stand-your-ground and castle doctrines are available as legal defenses to people who have been charged with crimes that involve the use of force, such as murder, manslaughter, aggravated assault, and illegal discharge or brandishing of weapons. Whether a person would succeed with such a defense would depend on the facts of their case and the judge or jury that decides their case.

An average citizen is allowed to use self-defense as a defense to a criminal charge of a violent crime. Self-defense is the use of reasonable force to protect oneself or members of one’s family from the threat of bodily harm or death by an aggressor.

Self-defense is only applicable if the defender has reason to believe that they or their family member is in immediate danger of serious physical harm or death. For a person to use lethal force in defense of themselves, they must be matching the force used by the perpetrator. It cannot be a mere excuse for using excessive force to harm or kill an opponent.

Do I Need a Lawyer for Help with Deadly Force Laws?

Deadly force laws vary widely from state to state and the federal government has its own laws and policy for FBI agents. These laws are very important, because they define the limits of the physical force that a police officer can use legally under given conditions.

The law of self-defense also varies and knowing the law in the state in which a person is charged is critically important.

If you need help with an issue that involves the use of deadly force, you should speak with a local criminal defense lawyer immediately. Your attorney will be able to analyze the facts of your case, explain your legal options and the course of action you should take.