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 Nebraska, the felony murder rule is codified in the state's statutes, specifically under Nebraska Revised Statute 28-303. This rule establishes that a person commits murder in the first degree if they kill another person while perpetrating or attempting to perpetrate any of several specified felonies, which include arson, robbery, burglary, kidnapping, and others. Under this rule, all participants in the felony can be held criminally responsible for a death that occurs during the commission of the felony, regardless of who actually caused the death. This means that accomplices such as lookouts or getaway drivers can be charged with first-degree murder even if they did not directly cause the victim's death. The rule applies even if the death was unintentional or accidental, and it can also apply if a co-felon is killed, for example, by law enforcement during the commission of the crime.