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 Delaware, the felony murder rule is codified in the state's criminal statutes. Specifically, under Delaware law, an individual can be charged with felony murder if someone dies during the commission of, or attempt to commit, certain felonies, even if the individual did not directly cause the death. The relevant felonies typically include those that are inherently dangerous, such as robbery, burglary, rape, kidnapping, arson, and similar offenses. This means that all participants in the felony, including lookouts or getaway drivers, can be held criminally responsible for a death that occurs during the commission of the felony, regardless of their intent or whether the death was accidental. Furthermore, this liability extends to situations where an accomplice is killed, for example, by law enforcement during the crime. Delaware's application of the felony murder rule reflects the doctrine's purpose to deter individuals from engaging in felonies that could foreseeably result in loss of life.