Penal Code 31 - California Aiding and Abetting Laws


Penal Code 31 PC is the California statute that defines aiding and abetting a crime. This section makes it illegal to encourage, facilitate or aid in the commission of a criminal act. A person who aids and abets a crime faces the same punishment as the one who directly commits the crime.

31 PC states that "all persons concerned in the commission of a crime, whether it be felony or misdemeanor, and whether they directly commit the act constituting the offense, or aid and abet in its commission...are principals in any crime so committed."

"Aiding and abetting" (also sometimes called "accomplice liability") is not a separate crime. Rather, it's a legal principle set forth in California's Penal Code that allows the state to prosecute everyone who is "in on" a crime - even if they don't perpetuate the crime directly. 

Example: Alan, Bill and Charlie plan out a bank robbery. Each plays a different role. Alan draws up a diagram of the teller windows and the safes. He gives it to Bill (after which Alan's role is done). Charlie drives Bill to the bank and waits out front in the getaway car. Bill actually goes in and robs the bank. Bill comes running out with the loot, jumps in the car, and Charlie drives the two of them off.

Technically speaking, only Bill did the actual "robbing." But prosecutors could charge all three with bank robbery: Bill as the direct perpetrator, Alan and Charlie as aiders and abettors. In Alan's case, he's liable for the robbery even though he wasn't even present at the crime scene.

You can be convicted of a crime under aiding and abetting theory, PC 31, even if you played a fairly insignificant role int he crime. But there must be some type of involvement before you can be convicted. Mere knowledge about the crime or presence at the scene will not suffice. 1, 2

And unlike a conspiracy, there needn't be a prior agreement to commit the face liability simply for your voluntary involvement.


Typical legal defenses put forward by a California defendant charged as an aider and abettor under Penal Code 31 PC include asserting that he:

  • did not encourage, aid or facilitate the crime's commission
  • was falsely accused
  • withdrew from participation in the criminal activity
  • was merely present at the scene, or perhaps even had knowledge about the crime, but had no duty to try to prevent its commission
  • only facilitated the crime after its commission (and should face, if anything, the lesser penalties as an "accessory after the fact").

Penalties for PC 31 Aiding and Abetting

An aider and abettor generally faces the same criminal charges under California's Penal Code as the direct perpetrator. If convicted, he typically also faces the same penalties.  In a murder case, for example, an aider and abettor typically faces life in prison just as does the one who commits the actual killing.

Below, our California criminal defense attorneys3 explain California's aiding and abetting laws...and the applicable defenses to these addressing the following:

If, after reading this article, you would like more information, we invite you to contact us at Shouse Law Group.

1. How does Calfornia law define aiding and abetting?

The phrase "aiding and abetting" means helping another person commit a crime.  Prosecutors can charge you as an aider and abettor when you

  1. know the perpetrator's illegal plan,
  2. intentionally encourage and/or facilitate that plan, and
  3. aid, promote, or instigate the crime.4

Despite the fact that it sounds as if you must encourage or promote the criminal activity in advance, that isn't necessarily the case.  Aiding and abetting may be committed as instantaneously as the crime itself.  If you become aware that a crime is being committed...and at that point, encourage, facilitate or promote its occurrence...the judge or jury can still find you guilty under an accomplice liability theory.5

trial jury box
If you are charged with aiding and abetting under PC 31, the jury will be asked to determine whether you acted knowingly and intentionally.

As far as "encouraging, facilitating or promoting" the offense, there is no requirement that your conduct be a substantial factor in the offense.  "Liability attaches to anyone 'concerned,' however slight."6

Common examples of aiding and abetting a crime include:

  • serving as a lookout,
  • keeping an engine running in a car, or
  • driving the "get-away" car.7

You can also be convicted of Penal Code 31 PC aiding and abetting even if you are legally incapable of committing the actual offense yourself.


Aiding and abetting rape

A deputy sheriff ordered a jail inmate to perform oral sex upon another inmate.  He was convicted of violating a California law that specifically prohibits inmates from engaging in oral copulation. In other words, the law makes it a crime for one inmate to engage in oral copulation with another inmate.

The deputy argued that because he was not an inmate, he couldn't be convicted of this particular crime.  The court disagreed, stating that "Under an aiding and abetting theory, a defendant can properly be convicted of a crime even though by statutory definition the defendant would be incapable of committing the substantive offense by himself".8

Aiding and abetting rape

Similarly, a woman cannot physically rape another woman, as rape necessarily involves intercourse.  However, if a woman encourages a man to rape another woman, serves as a lookout for that man, and/or arranges the meeting of the man and woman in a secluded location so that he can rape her, she could be prosecuted for rape under the accomplice liability theory.

While aiding and abetting may sound like the California crime of conspiracy - and although the two are closely related - "aiding and abetting" under PC 31 and conspiracy are actually two different offenses.  The major difference between the two is that for there to be a conspiracy there must be an agreement to participate in criminal activity.9 Whereas aiding and abetting does not necessarily require an agreement.

You may also find helpful our article on the difference between aiding and abetting.

1.1. When can the prosecutor charge someone as an accomplice?

With respect to the criminal allegation, the prosecutor doesn't "charge you" with aiding and abetting. Rather, under the California Penal Code, the prosecutor charges you with the underlying crime and presents the case on the theory that you acted as an aider and abettor.10

In determining whether you acted as an accomplice, among the factors to be considered are:

  • "presence at the scene of the crime,
  • companionship, and
  • conduct before or after the offense".11

Note that these are just some of the factors that help determine whether you should be charged as an accomplice. But they are not conclusive.  

1.2. Presence at the crime scene is not necessarily required for aiding and abetting liability

There is no requirement that you be present at the crime scene in order to be convicted under an accomplice liability/aiding and abetting theory.12 Neither must you physically or logistically assist in the commission of the crime. Instigating, encouraging or promoting the crime is sufficient.13 The test under PC 31 is whether you "in any way, directly or indirectly, aided the perpetrator by acts or encouraged him by words or gestures."14

Example: Defendant was convicted of insurance fraud for filing a false personal injury claim.  The co-defendant, the defendant's girlfriend, was the one who actually forged the necessary signatures and filed the claims.  The defendant knew the fraudulent claims had been filed and blatantly lied to the insurance investigator, saying he had received medical treatment (which he hadn't) and that he had to take time off work (which he didn't).  The defendant argued that because he didn't actually assist in filing the fraudulent paperwork, there was no accomplice liability.

The court disagreed.  It held that because defendant knew about the claims that were fraudulently filed on his behalf - and therefore had knowledge about the perpetrator's plan and encouraged its commission by lying, thus intending to defraud the insurance company - he was properly convicted on an aiding and abetting theory. This was the case despite the fact that he did not physically participate in the crime.15

1.3. Knowledge alone isn't sufficient to be guilty of aiding and abetting

Simply knowing that the crime is about to be (or is being) committed and failing to report it or prevent it generally isn't enough in and of itself to sustain a conviction for aiding and abetting.16 However, if you have a legal duty to take every step reasonably possible to prevent the crime...and fail to do could be convicted as an aider and abettor.

Just knowing about a crime beforehand is not enough to make you guilty of aiding and abetting under California's Penal Code.

This "legal duty" is only imposed on certain people under specific conditions.  For example, teachers, doctors and certain other professionals have a legal duty to report abuse or other suspected criminal activity.  And, in California, parents have a legal duty to "exercise reasonable care, supervision, protection, and control over their minor children".17

So if you have a legal duty to try to prevent a crime - but do not reasonably attempt to do so - you could face accomplice liability under Penal Code 31 PC.

Example: Defendant was convicted of committing lewd acts on a minor as an aider and abettor.  The prosecutor presented evidence that the defendant stood by and watched her boyfriend molest her 4-year-old daughter on more than one occasion.

The defendant argued that because she didn't encourage or participate in the lewd acts on the minor, she shouldn't be liable as an accomplice.  However, the court ruled that the defendant/mother's presence, in itself, assisted the boyfriend, since her presence not only encouraged the boyfriend to continue molesting her daughter but also encouraged her daughter to comply rather than resist.

Moreover, the court held that because the defendant had a legal duty to act (to protect her child)...yet failed to do so...she was properly convicted under an aiding and abetting theory.18

2. What are the best defenses to a PC 31 charge?

Fortunately, there are a variety of legal defenses that apply to accomplice liability that a skilled California criminal defense attorney could present on your behalf.  The following are some of the most common:

2.1. You did not encourage, aid, facilitate, etc. the crime's commission

If you didn't encourage, facilitate or otherwise aid in the commission of the crime in any way, you are not guilty of aiding and abetting.

Suppose, for example, you're a passenger in a car with some friends when the driver decides to go rob a liquor store. You remain in the car while he and another passenger barge into a 7-11, wave a gun, and take money from the cash register. But you weren't aware of their plan when you first got in the car...and you did nothing to help facilitate it. In this scenario, you were "merely present" and shouldn't be held liable for the robbery.

There is an infinite number of ways that the allegation that you aided, facilitated or encouraged a crime could have been misunderstood.  The bottom line is that if you didn't intentionally engage in one of these acts, you should be acquitted from any accomplice liability under Penal Code 31 PC.

2.2. False accusations

Because there need not be any physical proof that you aided and abetted another person in the commission of a crime, it is easy for someone falsely to accuse you of doing so.  This would most likely be the case if, for example, someone was trying to divert his/her own criminal culpability by fingering you as the mastermind of the operation.

It is common for perpetrators of a crime to falsely accuse someone else of aiding and abetting.

Anger, revenge or jealousy could also prompt someone to accuse you of being involved in a crime in which you played no part.

But as Riverside criminal defense attorney Michael Scafiddi19 explains, "Our law firm...comprised of former police investigators and district attorneys...knows the most effective ways to investigate cases and scrutinize witnesses to fight your false aiding and abetting charges and ensure that the truth comes to light."

2.3. You withdrew from participation in the criminal activity

If...before the commission of the charged crime(s) withdrew from participation by

  1. notifying the other people involved in the crime of your intention to withdraw from participation, and
  2. doing everything in your power to prevent the crime from going forward,

you can fight your aiding and abetting charges on this basis.20

Example: You and another person plan to rob a store.  You are responsible for being the lookout outside.  But as you get to the location, you decide you no longer want to participate. So you tell your crime partner that you are backing out.  You also try to persuade him not to go through with it.  He nevertheless decides to go ahead with the robbery on his own.  In the meantime, you call the police and place an anonymous tip that the store is about to be robbed.  Unfortunately, they arrive too late to prevent it.

Given these facts, a jury could reasonably find that you (1) effectively communicated your intent to withdraw from the robbery, and (2) tried to prevent its commission.  You would probably be acquitted of the robbery charges.

But let's change the facts.  Let's say that you still communicate your intent to withdraw and try to persuade the perpetrator to do the same.  But instead of calling the police, you simply leave and go home.  Under these circumstances, you really didn't do everything you could to prevent it. Therefore you probably would not prevail using a "withdrawal" defense.

2.4. You had no duty to act

It bears repeating that even if you know that a crime is going to be committed...but do nothing to prevent its are not guilty of being an aider and abettor under Penal Code 31 unless you have a legal duty to act.

And because legal duties are so few and far between...since they must be specifically conferred upon you by a law...they will not come into play very often.

As a result, mere knowledge of the underlying crime will not typically be enough to convict you as an aider and abettor.21

2.5. You only facilitated the crime after its commission

If you do help facilitate the crime...but only after it is are not an aider and abettor.  You may, however, be an accessory after the fact. (In contrast, aiding and abetting is sometimes called being an accessory before the fact.) Accessories after the fact are not treated in the same manner as accomplices under PC 31, but are instead treated as "obstructers of justice".22

Consequently, if you are convicted of being an accessory after the fact, you will most likely face a much lesser penalty than you would as an accomplice to the crime.  An aider and abettor to carjacking, for example, faces up to 9 years in prison (just as does the actual perpetrator). Whereas the maximum penalty for being an accomplice after the fact is three years in the California state prison.23

3. How is aiding and abetting a crime punished?

Each individual convicted of aiding and abetting under the California Penal Code will be regarded as a "principal" to the crime and is subject to the same penalties and consequences as if he/she personally committed the offense.24

prison watch tower
Under Penal Code 31, you face the same penalties for aiding and abetting as you do for directly committing the crime.

The only exception to this rule applies to murder prosecutions, discussed in the next section.25

3.1. Accomplice liability for murder

As the Supreme Court of California recognized, in some situations, an aider and abettor may be guilty of a greater homicide-related offense than the actual perpetrator, since defenses or extenuating circumstances may exist that are personal to the actual perpetrator and do not apply to the aider and abettor.26

Example:  Two defendants fire shots in a drive-by shooting. Only one defendant fires the shot that actually kills the victim.  He is labeled the perpetrator, and the other defendant ...who was riding in the passenger labeled the "aider and abettor".

If, for example, the perpetrator proves that he only fired that shot in
self-defense, his charge would be reduced to
voluntary manslaughter or possibly even dismissed.  However, the second defendant (the aider and abettor)...who still shot at and intended to kill the victim in the drive-by shooting...could still be convicted of murder.27

3.2. Natural and probable consequences

Aiders and abettors under PC 31 are not only equally responsible for the perpetrator's intended criminal activity. They are also equally responsible for any crimes that are the natural and probable consequences of that original crime.28

"Natural and probable consequences" are foreseeable consequences given all the surrounding circumstances.29 Whether a further crime is a "natural and probable consequence" of the original planned crime is a question that the jury must answer.30

Example: The defendant was in charge of driving the "get-away" car after the perpetrator robbed a jewelry store.  The perpetrator entered the store wearing a ski parka with a hood and sunglasses and carrying a brown paper bag that held a pillow.

While in the store, the perpetrator shot an employee in the face, and then shot and killed the store owner.  The defendant argued that he should not suffer accomplice liability for murder and attempted murder because he did not share in the perpetrator's intent to kill either victim.

The court disagreed.  It reasoned that "to 'share' the perpetrator's intent does not mean that the aider and abettor is prepared to commit the offense by his own act.  All that is needed is a knowing intent to assist the perpetrator's commission of the crime.  Once that intent is formed, the liability of an aider and abettor 'extends also to the natural and reasonable consequences of the acts he knowingly and intentionally aids and encourages'".

When the perpetrator entered the store with a gun and a pillow to muffle the sound of possible gunfire, the shootings were indeed a natural and probable consequence of the robbery itself.31

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Call us for help at (855) LAW-FIRM

If you or loved one is charged with Penal Code 31 PC aiding and abetting and you are looking to hire an attorney for representation, we invite you to contact us at Shouse Law Group. We can provide a free consultation in office or by phone. We have local offices in Los Angeles, the San Fernando Valley, Pasadena, Long Beach, Orange County, Ventura, San Bernardino, Rancho Cucamonga, Riverside, San Diego, Sacramento, Oakland, San Francisco, San Jose and throughout California.

To learn more about Nevada aiding & abetting law, go to our article on Nevada aiding & abetting law.

Legal References:

  1. California Penal Code 31 - Principals, defined [California Penal Code section on aiding and abetting].  ("All persons concerned in the commission of a crime, whether it be felony or misdemeanor, and whether they directly commit the act constituting the offense, or aid and abet in its commission, or, not being present, have advised and encouraged its commission, and all persons counseling, advising, or encouraging children under the age of fourteen years, or persons who are mentally incapacitated, to commit any crime, or who, by fraud, contrivance, or force, occasion the drunkenness of another for the purpose of causing him to commit any crime, or who, by threats, menaces, command, or coercion, compel another to commit any crime, are principals in any crime so committed.")

    California Jury Instructions - Criminal "CALJIC" 3.01 -- Aiding and Abetting.  ("A person aids and abets the [commission] [or] [attempted commission] of a crime when he or she: (1) With knowledge of the unlawful purpose of the perpetrator, and (2) With the intent or purpose of committing or encouraging or facilitating the commission of the crime, and (3) By act or advice, [or, by failing to act in a situation where a person has a legal duty to act,] aids, promotes, encourages or instigates the commission of the crime. [A person who aids and abets the [commission] [or] [attempted commission] of a crime need not be present at the scene of the crime.] [Mere presence at the scene of a crime which does not itself assist the commission of the crime does not amount to aiding and abetting.] [Mere knowledge that a crime is being committed and [in the absence of a legal duty to take every step reasonably possible to prevent the crime,] the failure to prevent it does not amount to aiding and abetting.]")

  2. See same.
  3. Our California criminal defense attorneys have local Los Angeles law offices in Beverly Hills, Burbank, Glendale, Lancaster, Long Beach, Los Angeles, Pasadena, Pomona, Torrance, Van Nuys, West Covina, and Whittier.  We have additional law offices conveniently located throughout the state in Orange County, San Diego, Riverside, San Bernardino, Ventura, San Jose, Oakland, the San Francisco Bay area, and several nearby cities.
  4. See CALJIC 3.01, Aiding and Abetting, endnote 1, above.
  5. People v. Swanson-Birabent (2003) 114 Cal.App.4th 733, 751-752.  ("Contrary to defendant's assertion, advance knowledge is not a prerequisite for liability as an aider and abettor. "Aiding and abetting may be committed 'on the spur of the moment,' that is, as instantaneously as the criminal act itself. [Citation.]" ( People v. Nguyen (1993) 21 Cal.App.4th 518, 532, 26 Cal.Rptr.2d 323.) In People v. Cooper (1991) 53 Cal.3d 1158, 282 Cal.Rptr. 450, 811 P.2d 742 ( Cooper ), the court held that "a getaway driver who has no prior knowledge of a robbery, but who forms the intent to aid in carrying away the loot during such asportation, may properly be found liable as an aider and abettor of the robbery." ( Id. at p. 1161, 282 Cal.Rptr. 450, 811 P.2d 742.) The court reasoned that "the commission of robbery continues so long as the loot is being carried away to a place of temporary safety." ( Id. at p. 1170, 282 Cal.Rptr. 450, 811 P.2d 742; see also People v. Montoya (1994) 7 Cal.4th 1027, 1039, 31 Cal.Rptr.2d 128, 874 P.2d 903 [upholding burglary conviction for aider and abettor who did not have knowledge of criminal purpose until after entry].)")
  6. People v. Durham (1969) 70 Cal.2d 171, 185, fn. 11.
  7. People v. Masters (1963) 219 Cal.App.2d 672, 680.
  8. People v. Fraize (1995) 36 C.A.4th 1722.
  9. California Penal Code 182 PC - Conspiracy.

    See also California Penal Code 184 PC - Conspiracy; overt act.  

  10. California Penal Code 971 PC -- Abrogation of distinction between accessories and principals, and between principals in first and second degree; effect upon pleadings.  
  11. People v. Singleton (1987) 196 Cal.App.3d 488, 492.
  12. See CALJIC 3.01 -- Aiding and Abetting, endnote 1, above.  
  13. People v. Booth (1996) 48 Cal.App.4th 1247, 1256.  ("While accomplice liability cannot be predicated on conduct absent the required mental state, one can be guilty as an accomplice (if he shares the goal of the perpetrator) without having actually assisted the commission of the offense, e.g., by "instigating," or "advising" the perpetrator to commit it or by having been "present for the purpose of its commission." (See Campbell, supra, 25 Cal.App.4th at p. 411, and cases cited.)")
  14. People v. Villa (1957) 156 Cal. App. 2d 128, 133.
  15. People v. Booth, endnote 13, above.
  16. See CALJIC 3.01 -- Aiding and Abetting, endnote 1, above.  ("[Mere knowledge that a crime is being committed and [in the absence of a legal duty to take every step reasonably possible to prevent the crime,] the failure to prevent it does not amount to aiding and abetting.]")
  17. Penal Code 272 PC California's contributing to the delinquency of a minor law, section (a)(2).
  18. People v. Swanson-Birabent, endnote 5, above.
  19. Riverside criminal defense attorney Michael Scafiddi uses his former experience as an Ontario Police Officer to represent clients throughout the Inland Empire including San Bernardino, Riverside, Rancho Cucamonga, Hemet, Banning, Fontana, Joshua Tree, Barstow, Palm Springs and Victorville.
  20. CALJIC 3.03 -- Termination of Liability of Aider and Abettor. 
  21. In re Michael T. (1978) 84 Cal.App.3d 907, 911.  ("Mere presence at the scene of a crime which does not itself assist its commission or mere knowledge that a crime is being committed and the failure to prevent it does not amount to aiding and abetting.")
  22. People v. Montoya (1994) 7 Cal.4th 1027, 1039, footnote 7.  ("[I]n accord[ ] with the clear trend, the accessory after the fact is no longer treated as a party to the underlying felony, as at common law. This kind of accessory is coming to be recognized for what he is: an 'obstructer' of justice, the author of a separate and independent offense."")
  23. California Penal Code 32 - Accessories, punishment.  ("Except in cases where a different punishment is prescribed, an accessory is punishable by a fine not exceeding five thousand dollars ($5,000), or by imprisonment in the state prison, or in a county jail not exceeding one year, or by both such fine and imprisonment.")
  24. California Penal Code 31 - California Penal Code section on aiding and abetting, endnote 1 above.

    See also People v. Green (1950) 96 Cal.App.2d 283, 290. (""Where persons are not actors in the actual commission of the crime charged, but aid and abet others in its commission or procure others to commit the crime, all are equally guilty.")

  25. CALJIC 3.00 Principals-Defined. 
  26. People v. Mccoy (2001) 25 Cal.4th 1111, 1122.  ("We thus conclude that when a person, with the mental state necessary for an aider and abettor, helps or induces another to kill, that person's guilt is determined by the combined acts of all the participants as well as that person's own mens rea. If that person's mens rea is more culpable than another's, that person's guilt may be greater even if the other might be deemed the actual perpetrator. Because we cannot anticipate all possible nonhomicide crimes or circumstances, we express no view on whether or how these principles apply outside the homicide context. (See Dressler, Understanding Criminal Law, supra, § 30.06[C], pp. 450-451.)")
  27. Facts taken from same.
  28. People v. Coffman (2004) 34 Cal.4th 1, 106-107.  ("Elaborating on the natural and probable consequences doctrine, in People v. Prettyman (1996) 14 Cal.4th 248, 261, 58 Cal.Rptr.2d 827, 926 P.2d 1013, and People v. Croy (1985) 41 Cal.3d 1, 12, footnote 5, 221 Cal.Rptr. 592, 710 P.2d 392, we observed that an aider and abettor "is guilty not only of the offense he intended to facilitate or encourage, but also of any reasonably foreseeable offense committed by the person he aids and abets." As the Court of Appeal in People v. Brigham (1989) 216 Cal.App.3d 1039, 265 Cal.Rptr. 486 noted, although variations in phrasing are found in decisions addressing the doctrine-"probable and natural," "natural and reasonable," and "reasonably foreseeable"-the ultimate factual question is one of foreseeability. ( Id. at pp. 1050, 1054, 265 Cal.Rptr. 486; see People v. Roberts (1992) 2 Cal.4th 271, 316-322, 6 Cal.Rptr.2d 276, 826 P.2d 274.) "A natural and probable consequence is a foreseeable consequence..."")

    See also CALJIC 3.02 Principals-Liability for Natural and Probable Consequences. 

  29. See both cites, endnote 28, above.
  30. People v. Godinez (1992) 2 Cal.App.4th 492, 499.  ("The parties agree the liability of an aider and abettor [as set forth in California Penal Code 31 PC] is not limited to the target crime which he knowingly and intentionally aids and encourages, but can include crimes committed by the perpetrator which are natural and reasonable consequences of the criminal course of conduct the aider and abettor knowingly aids and encourages. ( People v. Jones (1989) 207 Cal.App.3d 1090, 1095-1096 [ 255 Cal.Rptr. 464].) It is now settled that it is a question of fact whether the charged offense was a natural and reasonable consequence of the target offense knowingly encouraged, and the jury should be instructed of its responsibility to determine this factual issue.")
  31. People v. Hammond (1986) 181 Cal.App.3d 463.

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