California Murder Laws

California Penal Code 187

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California law penalizes the act of killing a person without legal justification. If the killing is accompanied by “malice aforethought,” it is considered murder instead of another offense such as manslaughter. People who are charged with this offense should understand the seriousness of the crime and the potential penalties that can result if they are convicted of murder.

Murder Definition

Under California law, murder is defined as the unlawful killing of another person with malice aforethought1. For a prosecutor to secure a conviction, he or she must be able to prove the following legal elements.

Unlawful Killing

There are some instances when a killing of another person is justified, such as in self-defense. Murder is the most aggravated form of homicide and occurs when there is no legal justification for it.

Malice Aforethought

The prosecutor must also show that there was “malice aforethought.” Aforethought means that this was before the commission of the crime. Malice can be express or implied.2 Express malice is present when the defendant has the intent to kill someone.3 Malice can be implied when there does not appear to be provocation that led to the killing or the defendant had no regard for human life.4 The prosecution must prove this malice; it is not enough to simply show the defendant participated in a crime.

Murder is an intentional killing. Under this definition, murder can also occur under these conditions:

  • The defendant committed an intentional act to carry out the killing
  • The natural consequences of the intentional act are dangerous to human life
  • The act was committed intentionally with knowledge of the danger to human life and the defendant consciously disregarded this knowledge

Malice aforethought does not require showing that the defendant harbored any ill will or hatred toward the victim. The relevant question is whether the defendant acted intentionally to kill the victim or in a way that was likely to lead to the victim’s death, not the rationale behind the killing.

Penalties for Murder

The potential penalty for murder depends on the degree of murder that is charged.

First Degree Murder

First degree murder is more serious and can result in harsher penalties. First degree murder charges can result when the murder is committed:

  • Through a willful, deliberate and premeditated act
  • By using a destructive device explosive, a weapon of mass destruction, ammunition primarily designed to penetrate metal or armor, or poison
  • By lying in wait
  • By torture
  • In the commission of a particular felony
  • Intentionally discharging a firearm from a motor vehicle with the intent to kill someone outside the vehicle5

First-degree murder carries a maximum penalty of death, life imprisonment without the possibility of parole or a prison sentence of 25 years to life, depending on the factors involved in the case.6

Second Degree Murder

Second degree murder is any other killing that is not within the definition of first degree murder.7 Second degree murder is typically subject to a maximum penalty of imprisonment of 15 years to life.8 However, there are some exceptions, such as:

  • The victim was a peace officer and killed during the performance of his or her duties and the victim knew or should have known the victim was a peace officer9
  • The defendant intentionally discharged a firearm from a motor vehicle with the intent to inflict great bodily injury to someone outside the vehicle10

Legal Defenses to Murder

Individuals charged with murder may be able to assert a number of legal defenses to this charge, such as:

  • Self-defense – The killing of another person may be justified when the defendant kills the person to protect themselves or another person from being killed, suffering great bodily harm, being robbed, being raped or being the victim of another serious crime. The defendant has the legal right in these circumstances to take whatever steps are reasonably necessary to protect against this harm.
  • Imperfect self-defense – This type of defense asserts that the defendant believed he or she was acting in self-defense but this belief turned out to be wrong. While this defense will not allow the defendant to fully escape criminal responsibility, it can justify a reduction in charges.
  • Accident – Because murder requires intent, if the killing occurred by accident that could not have reasonably been anticipated, the defendant should not be convicted of murder.
  • Mistaken identity – The defendant may have been mistakenly identified and someone else may have committed the crime.
  • Insanity – Individuals may be able to raise an insanity defense if they do not understand the nature of their act or cannot distinguish the difference between right and wrong.

Additionally, a criminal defense lawyer may attack the admissibility or credibility of the evidence, such as by showing the evidence was obtained through an illegal search and seizure, a confession was coerced or forensic evidence is tainted.

the killing amounted to a lesser form of homicide such as voluntary manslaughter, involuntary manslaughter or justifiable homicide.

Voluntary Manslaughter

Another possible defense is to establish that the killing occurred due to a sudden quarrel or heat of passion. In this situation, voluntary manslaughter may be charged instead.11


1 California Penal Code 187(a) PC – Defines murder as “the unlawful killing of a human being, or a fetus, with malice aforethought.”

2 California Penal Code 188(a) PC – (“Malice may be express or implied.”)

3 California Penal Code 188(a)(1) PC – (“Malice is express when there is manifested a deliberate intention to unlawfully take away the life of a fellow creature.”)

4 California Penal Code 188(a)(2) PC – (“Malice is implied when no considerable provocation appears, or when the circumstances attending the killing show an abandoned and malignant heart.”)

California Penal Code 188(a)(2) PC – (“In order to be convicted of murder, a principal in a crime shall act with malice aforethought. Malice shall not be imputed to a person based solely on his or her participation in a crime.”)

5 California Penal Code 189(a) PC – (“All murder that is perpetrated by means of a destructive device or explosive, a weapon of mass destruction, knowing use of ammunition designed primarily to penetrate metal or armor, poison, lying in wait, torture, or by any other kind of willful, deliberate, and premeditated killing, or that is committed in the perpetration of, or attempt to perpetrate, arson, rape, carjacking, robbery, burglary, mayhem, kidnapping, train wrecking, or any act punishable under Section 206, 286, 287, 288, or 289, or former Section 288a, or murder that is perpetrated by means of discharging a firearm from a motor vehicle, intentionally at another person outside of the vehicle with the intent to inflict death, is murder of the first degree.”)

6 California Penal Code 190(a) – (“Every person guilty of murder in the first degree shall be punished by death, imprisonment in the state prison for life without the possibility of parole, or imprisonment in the state prison for a term of 25 years to life. The penalty to be applied shall be determined as provided in Sections 190.1, 190.2, 190.3, 190.4, and 190.5.”)

7 California Penal Code 189(b) PC – (“All other kinds of murders are of the second degree.”)

8 California Penal Code 190(a) PC – Except as otherwise provided, “every person guilty of murder in the second degree shall be punished by imprisonment in the state prison for a term of 15 years to life.”

9 California Penal Code 190(b) PC – Provides a potential sentence range for 25 years to life for these conditions. See also California Penal Code 190(c) PC – Provides for imprisonment for life without the possibility of parole if any of the following conditions were present: the defendant specifically intended to kill the peace officer, the defendant specifically intended to inflict great bodily harm to the defendant; the defendant used a dangerous or deadly weapon in the commission of an offense; or, the defendant used a firearm in the commission of an offense

10 California Penal Code 190(d) PC – (“Every person guilty of murder in the second degree shall be punished by imprisonment in the state prison for a term of 20 years to life if the killing was perpetrated by means of shooting a firearm from a motor vehicle, intentionally at another person outside of the vehicle with the intent to inflict great bodily injury.”)

11 Judicial Council of California Criminal Jury Instruction, CALCRIM 570 – California’s voluntary manslaughter law. Explained as “The defendant killed someone because of a sudden quarrel or in the heat of passion if: [1] The defendant was provoked; [2] As a result of the provocation, the defendant acted rashly and under the influence of intense emotion that obscured (his/her) reasoning or judgment; AND [3] The provocation would have caused a person of average disposition to act rashly and without due deliberation, that is, from passion rather than from judgment.”