CALCRIM No. 520

(Pen. Code, § 187)

The defendant is charged [in Count] with murder [in violation of

Penal Code section 187].

To prove that the defendant is guilty of this crime, the People must

prove that:

[1A. The defendant committed an act that caused the death of

(another person/[or] a fetus);]

[OR]

[1B. The defendant had a legal duty to (help/care for/protect/rescue/

warn/maintain the property of/ <insert other required

action[s]>) <insert description of decedent/person to

whom duty is owed> and the defendant failed to perform that duty

and that failure caused the death of (another person/ [or] a

fetus);]

[AND]

2. When the defendant (acted/[or] failed to act), (he/she) had a state

of mind called malice aforethought(;/.)

<Give element 3 when instructing on justifiable or excusable homicide.>

[AND

3. (He/She) killed without lawful (excuse/[or] justification).]

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 had express malice if (he/she) unlawfully intended to kill.

The defendant had implied malice if:

1. (He/She) intentionally (committed the act/[or] failed to act);

2. The natural and probable consequences of the (act/[or] failure to

act) were dangerous to human life;

3. At the time (he/she) (acted/[or] failed to act), (he/she) knew (his/

her) (act/[or] failure to act) was dangerous to human life;

AND

4. (He/She) deliberately (acted/[or] failed to act) with conscious

disregard for (human/[or] fetal) life.

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.

An (act/[or] failure to act) is dangerous to human life if it involved a

high degree of probability that it would result in death.

<Applicable only to driving under the influence cases.>

[If you find that the defendant drove a motor vehicle while impaired by

(alcohol/[and] drugs), you may consider that as a factor in deciding

whether the defendant acted with conscious disregard for (human/[or]

fetal) life.]

[It is not necessary that the defendant be aware of the existence of a

fetus to be guilty of murdering that fetus.]

[A fetus is an unborn human being that has progressed beyond the

embryonic stage after major structures have been outlined, which

typically occurs at seven to eight weeks after fertilization.]

[(An act/ [or] (A/a) failure to act) causes death if the death is the direct,

natural, and probable consequence of the (act/ [or] failure to act) and

the death would not have happened without the (act/ [or] failure to 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/ [or] (A/a) failure

to 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.]

[(A/An) <insert description of person owing duty> has a legal

duty to (help/care for/rescue/warn/maintain the property of/

<insert other required action[s]>) <insert description of

decedent/person to whom duty is owed>.]

<Give in parental duty to protect cases.>

[A parent has a legal duty to protect (his/her) child when the parent

knows to a substantial degree of certainty that a life-endangering act has

occurred or is about to occur. This duty to protect does not require a

parent to place (him/her)self in danger of death or great bodily harm.]

<Give the following bracketed paragraph if the second degree is the only

possible degree of the crime for which the jury may return a verdict.>

CALCRIM No. 520 HOMICIDE

[If you find the defendant guilty of murder, it is murder of the second

degree.]

<Give the following bracketed paragraph if there is substantial evidence of

first degree murder .>

[If you decide that the defendant committed murder, it is murder of the

second degree, unless the People have proved beyond a reasonable doubt

that it is murder of the first degree as defined in CALCRIM No.

<insert number of appropriate first degree murder instruction>.]

New January 2006; Revised August 2009, October 2010, February 2013, August

2013, September 2017, March 2019, September 2019, March 2021, March 2024,

September 2024,* October 2025

* Denotes changes only to bench notes and other commentaries.