Justifiable & Excusable Homicides: Definitions & Examples

Instructor: Kenneth Poortvliet
When a human being kills another human being, it's called homicide. It may or may not be a crime, however. In this lesson, we will explore the circumstances where a homicide is not a crime.

I didn't mean to!

What if someone killed another person, but didn't mean to? Should he or she go to prison for murder anyway? After all, someone is dead. What if he was sleepwalking, or had a prescription drug reaction or was too young to know better? Should all these be treated the same?

Homicide v. Murder

A homicide occurs when one person kills another. This doesn't mean it's a crime. A homicide is a crime when someone kills another unlawfully. But what does this mean? Simply put, if there's a law against it, then it's unlawful. Homicide crimes consist of murder and manslaughter and each state has a written statute that specifies when killing is murder or manslaughter or because of negligence. A typical murder statute is:

  1. The unlawful killing,
  2. Of another human, and
  3. With premeditation.

So, if Arthur shoots Agnes how do we know if it is a crime? At this point, we don't. Ok, so what if Arthur bought a gun, practiced shooting, followed her, and hid in the bushes. Then, when she left work, he shot her. If these are the facts, then this was murder because Arthur shot another Agnes with premeditation by planning the shooting and carrying it out.

Can a killing be less than murder but still be illegal? Yes, and the answer lies in the intent of the killer. For murder, the intent element is premeditation. However, for manslaughter it might be something like this:

  1. The unlawful killing,
  2. Of another human, and
  3. Committed upon provocation from the victim.

Notice that everything is the same except the last element, the intent element. Let's look at this example. Arthur and Agnes get into a heated argument and she calls him horrible names. He gets angry and hits her, sending her backward where she strikes her head and dies. Is this murder? Where's the premeditation? In this case, he was provoked, so it is manslaughter.


Sometimes killing another, even with intent, might not be illegal. Of course, it depends upon the circumstances of the incident. For example, if Arthur is minding his own business and Agnes attacks him, the law allows for Arthur to claim self-defense. This is also spelled out in a statute:

Self Defense exists when the defendant:

  1. Was not the aggressor,
  2. Held a reasonable belief that he or she is in imminent danger of death or great bodily harm,
  3. Used the amount of force necessary to defend himself or herself.

This defense is called justification, and it means that a person did kill someone else under circumstances that would normally be a crime, but the defendant's actions were justified. This approach focuses on the act of the person and, if proven, completely exonerates the defendant. This also applies to the defense of others except that there is a reasonable belief that someone else is in danger of death or great bodily harm. In both of these, the person claiming self-defense cannot be the one who provoked that attack (the aggressor).

Other justification defenses include:

  • A police officer's killing in the line of duty: Officers must believe their life, others or the public is in imminent danger.
  • Necessity (lesser of two evils): To prevent a greater harm to society or others, the defendant chose an action that resulted in death.
  • Duress: The defendant is being coerced by someone to commit an act which causes death. For example, a bank manager robs his own bank because a bad guy is threatening his family. If a security guard is killed, then duress would apply. (Some jurisdictions consider duress an excuse rather than a justification).


Rather than looking at the act, the defense of excuse looks at the person. If it is proven that the person could not form the required intent to commit a criminal homicide, then the person is excused. This defense does not claim that the person didn't commit a criminal homicide, but that the defendant wasn't capable of forming criminal intent.

For example, 20-year-old Jamie is mentally handicapped with an IQ below 50. He picks up his father's gun and points it at a friend and pulls the trigger killing the friend. At trial, Jamie's attorney must prove that Jamie is mentally handicapped to the degree that he can't appreciate right from wrong, thus isn't able to form the required intent to commit a criminal homicide.

Other defenses of excuse include:

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