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Homicide Crimes: Murder

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A homicide is a broad class of crimes where an individual takes the life of another individual. At common law, criminal homicide is divided into three categories: murder, voluntary manslaughter, and involuntary manslaughter.

The purpose of this article is to discuss murder. This article will define murder and its elements, differentiate the two classifications of murder, present potential defenses, and provide the regulations on sentencing for murder.

Murder Classifications

The legal definition of murder is “the unlawful taking of the life of another human being, with malice aforethought.”[1] Malice aforethought is a legal term of art meaning that the person acted with a “reckless indifference to an unjustifiable high risk to human life” or had a premeditated intent to kill.  

State law typically breaks murder down into two classifications: first-degree and second-degree. Both are first-degree felonies, but the distinguishing feature is the presence or absence of premeditation, or planning, on the part of the murderer.[2]

First Degree Murder

Murder in the first degree is murder committed with premeditation and deliberation. To be guilty of first-degree murder, the defendant must INTEND to kill. Even though an intention to kill is not necessary, first-degree murder implies that the defendant had “an element of coolness, of calm reflection.”[3] First-degree murder is not a universally recognized term. In some states, first-degree murder is called “aggravated murder.”[4]

In many states, a killing committed during the commission of an enumerated felony, felony murder, is first-degree murder. In their statutes, states provide a non-exhaustive list of the various felonies that can be charged as felony murder and these felonies include arson, burglary, rape, and kidnapping.

Second-Degree Murder

Any murder that is not first-degree murder is called second-degree murder. Murder in the second-degree is an intentional killing that is not premeditated or planned, but is committed by a person having a depraved heart or mind.[5]

Second-degree murder can arise in the following scenarios: killing done in the heat of the moment and a killing that results from an intent to cause serious bodily harm. In both situations, the killer is not intending to kill his victim, but he knows that death is a likely outcome of his actions.

Defenses to Murder: Excuses and Justifications

If a defendant successfully asserts one the following defenses to a murder charge, he can reduce the level of the crime, or be exonerated of the crime entirely.

Defenses to a murder charge can either be a justification or an excuse. Justification defenses focus on the act and NOT the actor. This means that a justification absolves an individual of criminal conduct because the individual’s conduct was judged to be useful to society.[6] On the other hand, an excuse absolves an individual of a homicide because he is not blameworthy due to extenuating circumstances.[7]



The most well-known excuse to both types of murder is insanity. There are several different tests that are applied in different states to determine insanity, but the reasoning behind undergirding each of the tests is that the defendant was so mentally ill that he is entitled to acquittal. Under the first method, known as the traditional M’Naghten Rule to Insanity, a defendant is entitled to acquittal if:

(1)  He has a disease of the mind;

(2)  The disease caused a defect of reason; and

(3)  The defect of reason precluded the defendant from being able to understand the nature and quality of his actions[8]

The second method of determining a defendant’s insanity is the irresistible impulse test. A defendant is excused and deemed to be insane if because of his mental illness, he was unable to control his actions or confirm his conduct to the law when he killed another person.

The third method of determining insanity is called the Durham Test. The Durham Test, broader than both M’Naghten and the irresistible impulse test, excuses a defendant’s conduct if the killing was the product of his mental illness.[9]


The second excuse used to negate criminal capacity in a murder is intoxication. Intoxication can either be voluntary or involuntary.

Voluntary intoxication is the voluntary and intentional taking of a substance known to be intoxicating, such as drugs or alcohol. Voluntary intoxication is a defense to first-degree murder because it can prevent a defendant from formulating the mental intent and premeditation required to purposely kill another individual. Involuntary intoxication is when a defendant ingests an intoxicating substance without knowledge of its nature, by mistake, under duress, or pursuant to medical advice.[10]



Self-defense is the use of force against another person to repel an unprovoked attack. A successful self-defense claim requires the following elements:

(1)  The defendant was a victim of an unlawful attack;

(2)  The defendant did not provoke the attack;

(3)  The defendant actually and reasonably believed that he was in imminent danger of bodily harm;

(4)  The defendant used only the amount of force necessary to repel the attack

With the fourth element, a person may use force as the person reasonably believes is necessary to protect himself from the imminent use of unlawful force upon him. Deadly force can only be used if the victim reasonably believes that he is threated with imminent death or great bodily harm. The aggressor in a deadly confrontation can use deadly force in self-defense if the victim of the initial minor confrontation escalates it into a deadly altercation and the aggressor is unable to withdraw from the fight.

Defense of Others

A defendant can also claim defense of others as a justification for murder. The defendant’s actions are justified if he is defending others and he has a reasonable belief that the person he is defending could use force in his own defense.

Defense of Dwelling

Under the Castle Doctrine, a person can use deadly force to prevent a violent entry and the property owner reasonably believes that the use of force is necessary to prevent a personal attack on himself or anybody else in the dwelling. This justification is unlike the defense of property, other than one’s home, where deadly force may NEVER be used to defend these other kinds of property.

Sentencing for Murder

In the eighteen states that have adopted capital punishment, the death penalty can only be imposed in cases where a defendant has been convicted of first-degree murder.

Federal sentencing guidelines require the death penalty or life without parole for first-degree murder, and life without parole for second-degree murder. Different states, of course, have a variety of penalties for murder. Aggravating (increasing) and mitigating (decreasing) circumstances play a role in the amount of time a person convicted of murder will be sentenced to. Mitigating circumstances include the above-referenced defenses, as well as whatever other concerns the sentencing judge wants to use. Aggravating circumstances comprise a very long list by state, and include the death of a pregnant woman’s fetus, prior convictions, cop killing, torture, ambush, and others.

Minimum sentences for second-degree murder vary widely throughout the states. For example, Arkansas has a six-year minimum, while Florida imposes a twenty-five-year sentence if a firearm is used during the killing. 


[1] "Murder," Legal dictionary. Retrieved from http://dictionary.law.com/Defulat.aspx?selected=1303.

[2] Michael Mannheimer, Not the Crime but the Cover-Up: A Deterrence-Based Rationale for the Premeditation-Deliberation Formula+, 86 Ind. L.J. 879, (2011).

[3] Matthew A. Pauley, Murder by Premeditation, 36 Am. Crim. L. Rev. 145, (1999).

[4] Ohio Revised Code § 2903.01

[5] John Scheb, Criminal Law, (2011).

[6] Joshua Dressler, Understanding Criminal Law, (2001).

[7] Eugene Milhizer, Justification and Excuse: What They Were, What They Are, And What They Ought To Be, 78 St. John's L. Rev. 725, (2004).

[8] Charles Fischette, Psychopathy and Responsibility, 90 Va. L. Rev. 1423 (2004).

[9] J.C. Oleson, Is Tyler Durden Insane?, 83 N.D. L. Rev. 579, (2007).

[10] David Levinson, Encyclopedia of Crime and Punishment, (2002).