Penal Code 187- Murder Defenses Used In Cases

Penal Code section 187 prohibits an unlawful killing of a human being or fetus with malice aforethought.  Below are 7 important things you should know about murder cases.

How Does The Prosecutor Prove Murder?

To prove that you are guilty of murder, the prosecutor has to prove the following facts or elements1:

  • The defendant committed an act that caused the death2 of another person or a fetus3; AND
  • When the defendant acted, he/she had a state of mind called malice aforethought4
  • He/she killed without lawful excuse or justification5

Establishing Malice Aforethought:

To establish that the defendant had the state of mind required for murder, you have to prove he/she acted with malice aforethought6

There are two kinds of malice aforethought, express malice and implied malice.  Proof of either is sufficient to establish the state of mind required for murder.  The defendant acted with express malice if he/she unlawfully intended to kill.  The defendant acted with implied malice if7:

  • He/she intentionally committed an act;
  • The natural and probable consequences of the act were dangerous to human life;
  • At the time they acted, they knew their act was dangerous to human life; AND
  • They deliberately acted with conscious disregard for human or fetal life. 
Malice Aforethought

Malice aforethought essentially means the same thing as acting with a premeditated intent to kill or extreme indifference to human life. Both first and second degree murder require malice.  Whereas the first degree murder requires a premeditated and deliberate intent to kill, second degree murder is murder without premeditation and deliberation.


John intended to kill Brice.  When the two went out to dinner and Brice went to the bathroom, John followed him and stabbed him to death in the stomach.  John’s intent to kill Brice fulfills the malice requirement under murder.  In this case, the malice was express.  Because John had a weapon on him and he had intent to kill Brice, the jury will likely find that John deliberated and premeditated.  As such, John could be convicted of first degree murder.

First Degree Murder

The following are ways that a defendant can be proven to have committed 1st degree murder in California8

  • The defendant acted willfully, deliberately, and with premeditation ((The defendant acted willfully if he/she intended to kill.  The defendant acted deliberately if he/she carefully weighed the considerations for and against his/her choice and, knowing the consequences, decided to kill. The defendant acted with premeditation if he/she decided to kill before completing the act[s] that caused death.  The length of time the person spends considering whether to kill does not alone determine whether the killing is deliberate and premeditated.  The amount of time required for deliberation and premeditation may vary from person to person and according to the circumstances. A decision to kill made rashly, impulsively, or without careful consideration is not  deliberate and premeditated.  On the other hand, a cold, calculated decision to kill can be reached quickly.  The test is the extent of the reflection, not the length of time. 9
  • The defendant murdered by torture if:10
  • He/she willfully, deliberately, and with premeditation intended to inflict extreme and prolonged pain on the person killed while that person was still alive11;
  • He/she intended to inflict such pain on the person killed for the calculated purpose of revenge, extortion, persuasion, or any other sadistic reason12;
  • Lying in wait: The defendant is guilty of first degree murder if the prosecutor has proved that the defendant murdered while lying in wait or immediately thereafter. The defendant murdered by lying in wait if13:
  • He/she concealed his/her purpose from the person killed14;
  • He/she waited and watched for an opportunity to act15;


  • Then, from a position of advantage, he/she intended to and did make a surprise attack on the person killed16
  • Defendant used destructive device/explosive; weapon of mass destruction; penetrating ammunition; discharge from vehicle to murder
  • Defendant Used Poison to Murder
  • Defendant killed by way of Felony Murder Rule:  This type of murder only attaches if it occurs during the commission of what is called an “inherently dangerous” felony.  The list of such felonies includes but is not limited to the following: Burglary, Arson, Robbery, Rape, Kidnapping, Mayhem.
  • The act was committed by a holder of a physician’s and surgeon’s certificate, as defined in the Business and Professions Code, in a case where, to a medical certainty, the result of childbirth would be death of the mother of the fetus or where her death from childbirth, although not medically certain, would be substantially certain or more likely than not;Under Penal Code section 187 pc, anyone who commits an unlawful killing of a human being, or a fetus, with malice aforethought can be charged with murder.  However, note that the section does not apply to the following acts that result in the death of a fetus:
  • The act complied with the Therapeutic Abortion Act, Article 217 of Chapter 2 of Part 2 of Division 106 of the Health and Safety Code;
  • The act was solicited, aided, abetted, or consented to by the mother of the fetus.

Second Degree Murder

Second degree murder is any murder that is not first degree murder.  Under Penal Code Section 187, second degree murder is also committed willfully but without premeditation and deliberation.


Sammie had a strong dislike for the parking enforcement officer in his neighborhood who always waited for somebody to be late in depositing more coins into the meter and issued a ticket right away.  One day, when Sammie saw the officer getting out his car, he decided to teach the officer a lesson.  Sammie got in his car and accelerated, driving so close to the officer’s car that his car hit the officer and ripped the officer’s door out completely.  The officer died on the spot.  Sammie can be charged with murder, because his mental state meets the implied malice requirement for murder because he intentionally committed the act of driving dangerously close to the officer’s car; the natural and probable consequences of the act were dangerous to the officer’s life; at the time he drove so close to the officer’s car, he knew that his act was dangerous to the officer’s life; and he deliberately acted with conscious disregard for the officer’s life.  If the jury decides that he premeditated and deliberated prior to committing the act, he could be charged with first degree murder.  If not, then he could be charged with second degree murder.

How Can You Fight Murder Charges & What Are the Defenses?

Self Defense Or Defense Of Others

To succeed on this defense, a defendant must show that the killing resulted from a reasonable use of force to resist a reasonable fear of death or bodily harm.  The degree of force used in self-defense must be proportional to the threat perceived, and the threat perceived must be something that would place a reasonable person in fear of death or great bodily harm. Mere words or insults do not suffice.  Defense of others,  the same requirements as for self-defense apply.  The use of force must be timely and proportional to the threat faced, and the perceived threat of death or bodily harm must be reasonable.

Insanity Defense

A defendant can plead not guilty by reason of insanity.  To succeed on this defense under California law, the defendant has to meet the McNaughten test of insanity.  Specifically, he/she has to show that as a result of a mental disorder, he/she either did not know the wrongfulness of his/her act OR could not understand the nature and quality of his/her acts (i.e. did not understand right from wrong).

Accidental Killing

An accidental killing committed during lawful events does not meet the requirements of a murder.  However, if an accidental killing occurs during the commission of a crime, it could be considered murder.

Mistaken Identity

A defendant can use this defense if he believes that the prosecution has charged the wrong person with the murder.  A defendant who uses this defense usually asserts an alibi with supporting evidence to prove that he/she was somewhere else at the time of the murder.

Penalties & Punishment For Murder

First Degree Murder: 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.

  • Hate Crime: If the murder was a “hate crime,” meaning, a crime committed based on the victim’s race, religion, gender, disability, sexual orientation, or nationality, the defendant will face a prison sentence for life without the possibility of parole.

Second Degree Murder: 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.

  • Killing a Peace Officer: every person guilty of murder in the second degree shall be punished by imprisonment in the state prison for a term of 25 years to life if the victim  was a peace officer if the circumstances meet the requirements under this section. 
  • Shooting Out of a Vehicle: 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 he/she killed the victim by shooting a firearm out of a vehicle with the intent of causing serious injury.
  • Prior Murder Conviction: every person guilty of murder in the second degree shall be punished by imprisonment for life without the possibility of parole if he/she has previously served a sentence for a murder conviction.

Related Offenses

How We Can Help

Your attorney should know all of the plausible defenses that apply to your case and should have the resources, the skill and experience to apply the defenses to get you the best outcome possible.   The California criminal defense attorneys at the Aizman Law Firm know the law. We have assembled the industry’s best team of former prosecutors, experts, investigators and researchers.  We have the skills, experience and knowledge necessary to protect your rights and get you the results you deserve.

If you would like to speak to an attorney about a pending case please contact our office at: (818) 351-9555 for a free confidential consultation.

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  1. California Penal Code 187 ; CALCRIM No. 520. []
  2. An act causes death if the death is the direct, natural, and probable consequence of the act and the death would not have happened without the act.  A natural and probable consequence is one that a reasonable person would know is likely to happen if nothing unusual intervenes.  In deciding whether a consequence is natural and probable, consider all of the circumstances established by the evidence.  There may be more than one cause of death.  An act causes death only if it is a substantial factor in causing the death.  A substantial factor is more than a trivial or remote factor.  However, it does not need to be the only factor that causes the death.  Causation.  People v. Roberts (1992) 2 Cal.4th 271, 315–321 [6 Cal.Rptr.2d 276, 826 P.2d 274]; CALCRIM 520. []
  3. A fetus is an unborn human being that has progressed beyond the embryonic stage after major structures have been outlined, which occurs at seven to eight weeks of development.  It is not necessary that the defendant be aware of the existence of a fetus to be guilty of murdering that fetus.  Fetus Defined.  People v. Davis (1994) 7 Cal.4th 797, 814–815 [30 Cal.Rptr.2d 50, 872 P.2d 591]; People v. Taylor (2004) 32 Cal.4th 863, 867 [11 Cal.Rptr.3d 510, 86 P.3d 881; CALCRIM 520]. []
  4. Malice aforethought does not require hatred or ill will toward the victim.  It is a mental state that must be formed before the act that causes death is committed.  It does not require deliberation or the passage of any particular period of time.  Ill Will Not Required for Malice.  People v. Sedeno (1974) 10 Cal.3d 703, 722 [112 Cal.Rptr. 1, 518 P.2d 913], overruled on other grounds in People v. Flannel (1979) 25 Cal.3d 668, 684, fn. 12 [160 Cal.Rptr. 84, 603 P.2d 1]; People v. Breverman (1998) 19 Cal.4th 142, 163 [77  Cal.Rptr.2d 870, 960 P.2d 1094]. []
  5. If there is sufficient evidence of excuse or justification, this third has to be included.  People v. Frye (1992) 7 Cal.App.4th 1148, 1155–1156 [10 Cal.Rptr.2d 217]). []
  6. Malice. Penal Code Section 188; People v. Dellinger (1989) 49 Cal.3d 1212, 1217–1222 [264 Cal.Rptr. 841, 783 P.2d 200]; People v. Nieto Benitez (1992) 4 Cal.4th 91, 103–105 [13 Cal.Rptr.2d 864, 840 P.2d 969]; People v. Blakeley (2000) 23 Cal.4th 82, 87 [96 Cal.Rptr.2d 451, 999 P.2d 675]. []
  7. Mental State Required for Implied Malice.  People v. Knoller (2007) 41 Cal.4th 139, 143 [59 Cal.Rptr.3d 157, 158 P.3d 731; []
  8. Types of Statutory First Degree Murder. Penal Code 189. []
  9. Premeditation and Deliberation Defined.  People v. Anderson (1968) 70 Cal.2d 15, 26–27 [73 Cal.Rptr. 550, 447 P.2d 942]; People v. Bender (1945) 27 Cal.2d 164, 183–184 [163 P.2d 8]; People v. Daugherty (1953) 40 Cal.2d 876, 901–902 [256 P.2d 911]. []
  10. For Torture, Act Causing Death Must Involve a High Degree of Probability of Death.  People v. Cook (2006) 39 Cal.4th 566, 602 [47 Cal.Rptr.3d 22, 139 P.3d 492]: []
  11. A person commits an act willfully when he or she does it willingly or on purpose.  A person deliberates if he or she carefully weighs the considerations for and against his or her choice and, knowing the consequences, decides to act. An act is done with premeditation if the decision to commit the act is made before the act is done. []
  12. There is no requirement that the person killed be aware of the pain.  A finding of torture does not require that the defendant intended to kill.  Torture Requirements.  People v. Pensinger (1991) 52 Cal.3d 1210, 1239 [278 Cal.Rptr. 640, 805 P.2d 899]; People v. Bittaker (1989) 48 Cal.3d 1046, 1101 [259 Cal.Rptr. 630, 774 P.2d 659], habeas corpus granted in part on other grounds in In re Bittaker (1997) 55 Cal.App.4th 1004 [64 Cal.Rptr.2d 679]; People v. Wiley (1976) 18 Cal.3d 162, 168–172 [133 Cal.Rptr. 135, 554 P.2d 881]; see also People v. Pre (2004) 117  Cal.App.4th 413, 419–420 [11 Cal.Rptr.3d 739] [comparing torture murder with torture]. []
  13. Lying in Wait Requirements.  People v. Stanley (1995) 10 Cal.4th 764, 794 [42 Cal.Rptr.2d 543, 897 P.2d 481]; People v. Ceja (1993) 4 Cal.4th 1134, 1139 [17 Cal.Rptr.2d 375, 847 P.2d 55]; People v. Webster (1991) 54 Cal.3d 411, 448]; People v. Poindexter (2006) 144 Cal.App.4th 572, 582–585 [50 Cal.Rptr.3d 489]; People v. Laws (1993) 12 Cal.App.4th 786, 794–795 [15 Cal.Rptr.2d 668] []
  14. A person can conceal his or her purpose even if the person killed is aware of the person’s physical presence. []
  15. The lying in wait does not need to continue for any particular period of time, but its duration must be substantial enough to show a state of mind equivalent to deliberation or premeditation.  Deliberation means carefully weighing the considerations for and against a choice and, knowing the consequences, deciding to act. An act is done with premeditation if the decision to commit the act is made before the act is done. []
  16. The concealment can be accomplished by ambush or some other secret plan. []
  17. commencing with Section 123400 []

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