The Natural and Probable Consequences Doctrine in California
What is “natural and probable consequences law?” How has it changed?
The Natural and Probable Consequences Doctrine was a theory of criminal liability that allowed a person to be convicted of serious crimes—including murder—even if they did not intend, anticipate, or directly participate in the ultimate offense, so long as it was deemed a “natural and probable” result of a lesser crime.
That doctrine has been fundamentally changed—and largely eliminated—for murder and attempted murder cases in California.
The governing statute is California Penal Code §188, as amended by Senate Bill 1437 and clarified by Senate Bill 775.
What the Doctrine Used to Mean
Under the former rule, prosecutors could argue:
If you intentionally aided or encouraged a lesser crime, you could be held criminally responsible for any more serious crime that was a natural and probable consequence of that act—even if you never intended it.
This meant a defendant could face:
- Murder liability
- Attempted murder liability
- Life-sentence exposure
The murder liability was based on foreseeability, not intent. While this was good-intentioned–it led to an enormous amount of unjust sentences that filled the California prison system beyond capacity.
How the Doctrine Was Used in Practice
Before reform, the doctrine was commonly used in cases involving:
- Group altercations
- Gang allegations
- Robberies or burglaries involving multiple people
- Situations where one participant escalated violence unexpectedly
A defendant could be convicted of murder even if:
- They did not know a weapon would be used
- They did not intend serious injury
- They were not present when the killing occurred
This led to extreme sentencing outcomes for peripheral participants.
The Statutory Change: SB 1437
In 2018, the Legislature passed Senate Bill 1437. SB 1437 eliminated the natural and probable consequences doctrine as a basis for murder liability.
Key Changes Under Penal Code §188
Penal Code §188 now requires that, for murder:
- The defendant must act with malice aforethought
- Malice cannot be imputed based solely on participation in a crime
- A person cannot be convicted of murder unless they:
- Personally killed,
- Intended to kill, or
- Were a major participant acting with reckless indifference to human life (felony murder context)
Foreseeability alone is no longer enough.
What About Attempted Murder?
Initially, there was confusion about whether SB 1437 applied to attempted murder. That issue was resolved by Senate Bill 775 (effective 2022).
SB 775 clarified that:
- The natural and probable consequences doctrine cannot be used to convict someone of attempted murder
- Relief applies both prospectively and retroactively
This closed a major loophole that prosecutors had continued to exploit.
When the Doctrine No Longer Applies
Today, the doctrine cannot be used to support:
- Murder convictions
- Attempted murder convictions
- Murder special circumstances
- Vicarious malice theories based solely on group conduct
If the prosecution’s theory rests on:
- “You should have known”
- “It was foreseeable”
- “Someone else escalated”
This theory is legally insufficient under current law.
What Liability Still Exists
This reform does not eliminate all accomplice liability. A defendant may still be criminally responsible if prosecutors can prove:
- Direct aiding and abetting with intent
- Personal use of force or weapons
- Major participant + reckless indifference (in limited felony-murder cases)
The key difference is intent and culpability must be proven—not assumed.
Why This Matters in Active and Prior Cases
These changes affect:
- Current charging decisions
- Plea negotiations
- Jury instructions
- Sentencing exposure
- Post-conviction relief and resentencing
Many older convictions were obtained under theories that are no longer lawful. Others are still being overcharged based on outdated assumptions.
Bottom Line
The natural and probable consequences doctrine no longer supports murder or attempted murder liability in California. Its abolition represents a major shift toward individual culpability rather than guilt by association.
But the doctrine’s legacy still shows up in police reports, charging documents, and prosecutorial arguments—especially in multi-defendant cases.
Next Step
If you or a family member is facing a murder or attempted murder charge in California—and you want a defense review focused on whether the prosecution is relying on outdated or unlawful liability theories under Penal Code §188—you can send your information to me here: