Homicide is defined as the killing of one human being by another. Although homicides are generally thought of as criminal acts, such as murder or manslaughter, some homicides are considered lawful because they are “justified” for reasons such as self-defense. According to the Department of Justice, the rate of homicide in the United States has declined dramatically in recent years, falling to almost half in the past decade. The rate of homicide remains the greatest amongst young adults age 18-24, and males are over three times more likely to commit a homicide than females.

Homicide encompasses a variety of criminal offenses, and the specific homicide offense charged in a crime depends on the defendant’s mental state and intentions at the time of the killing.


Murder is an intentional killing that is unlawful and was committed with “malice aforethought.” Malice aforethought means that the defendant had the intent to harm or kill another, or acted with reckless disregard for another’s life.  When considering murder charges, many states distinguish murders that are particularly egregious as first-degree murders. Although the exact requirements may vary by state, first-degree murder is the strictest form of homicide and generally requires that the defendant acted in a deliberate and premeditated manner. Premeditation requires that the defendant had, in some way, considered killing another person and acted consciously in doing so.

Second-degree murder occurs when the defendant may have intended to kill, but lacked premeditation. A conviction for second-degree murder usually results in punishment that is slightly less severe than the punishment imposed for first-degree murder.

Under the felony murder rule, defendants can also be held liable for a homicide that occurs in the commission of another crime they are participating in, even if they did not commit the homicide themselves. Thus, if a defendant is participating in a burglary where his partner kills another, the defendant can be charged with homicide under the felony murder rule if the crime occurred in a jurisdiction that recognizes that rule. Felony murder typically applies only where the underlying crime is a serious one. This will vary by state and is set forth in state penal codes.


Manslaughter is an unlawful killing that does not involve malice aforethought. Because manslaughter is not intentional or premeditated, it is generally subject to a lower punishment than murder. The two primary forms of manslaughter are voluntary manslaughter and involuntary manslaughter.

Voluntary manslaughter is similar to second-degree murder, as it typically involves a killing that occurs in the “heat of passion.” This means a sudden and intense passion that causes the defendant to lose control. One common example of voluntary manslaughter is where a husband unexpectedly encounters his wife in an act of adultery and acts violently as a result.

Involuntary manslaughter is the least serious degree of homicide and arises when a defendant did not intend to kill another, but acted with a carelessness or reckless indifference to a substantial risk, resulting in the death of another. A common example is driving under the influence of alcohol (DUI) and causing the death of another person as a result. The drunk driver did not intend to kill, but she acted with reckless indifference to the possible consequences of driving drunk.

Many states also have statutes that set forth a particular crime for those who negligently or recklessly cause the death of another while driving a vehicle. This is often referred to as vehicular manslaughter or vehicular homicide.