The felony murder rule is a legal doctrine that expands the definition of murder and makes criminal accomplices (including a lookout or getaway driver) as responsible for a death that occurs in the course of a dangerous felony crime as the person who directly caused the death by pulling the trigger of a gun, stabbing the victim with a knife, strangling the victim, or otherwise causing the victim’s death. Examples of dangerous felony crimes that implicate the felony murder rule include robbery, burglary, rape, aggravated kidnapping, carjacking, and arson.

When the felony murder rule applies, it may make a criminal accomplice liable for murder even if the criminals had agreed that no one would be killed in the course of the crime, and even if it is a fellow criminal who is killed in the course of the crime—such as when a police officer or security guard shoots a bank robber—which may result in all other accomplices to the crime being charged with murder.

In many states the felony murder rule—and any distinctions between the culpability of accomplices and principals to a crime—are located in the state’s statutes—often in the penal or criminal code.

In California, the felony murder rule is codified in the California Penal Code Section 189(e). This rule holds that a defendant can be charged with murder if a death occurs during the commission or attempted commission of certain felonies, even if the defendant did not intend to kill or did not directly cause the death. The underlying felonies typically include inherently dangerous felonies such as robbery, burglary, rape, kidnapping, arson, and carjacking. The rule applies to all participants in the felony who act with reckless indifference to human life, and it can result in murder charges even if the death was accidental or caused by a co-participant or law enforcement during the crime. However, recent changes to the law with the passage of Senate Bill 1437 have narrowed the application of the felony murder rule in California. As of 2019, accomplices can only be convicted of felony murder if they were a major participant in the underlying felony and acted with reckless indifference to human life, or if they actually killed the victim. This reform was intended to ensure that individuals are not disproportionately punished for murders they did not commit or plan.