A lesser included offense (or “necessarily” included offense) is a criminal law term for a crime that’s contained within a greater crime—you can’t commit the greater offense without committing the lesser.
To determine whether one crime is necessarily included within another, courts have used at least three tests.
To determine whether a crime is "lesser included," some courts have looked at the way the charging document describes the charge against the defendant. Take murder and assault with a deadly weapon, for example. If an indictment charged that a murder occurred by stabbing, then assault with a deadly weapon would be a lesser included offense. That’s because, if the defendant did in fact commit murder by stabbing, he necessarily also committed assault with a deadly weapon (the deadly weapon, of course, being the knife). (Michael H. Hoffheimer, “The Rise and Fall of Lesser Included Offenses,” 36 Rutgers L.J. 351 (2005).)
Some courts have determined whether an offense is “lesser included” by looking not at the charging document, but at the evidence actually presented by the prosecution. So, if the prosecution charged the defendant with murder and presented evidence that the homicide occurred by stabbing, then assault with a deadly weapon would again be a lesser included offense. (Hoffheimer, supra.)
The most popular approach to identifying lesser included offenses among courts is the elements test. This test doesn’t look at the charging document or the evidence. Instead, it considers only the definitions of the crimes standing on their own.
This test provides that a more serious crime contains all the elements of a lesser included crime, plus one or more other elements. Under this test, regardless of the pleadings or the evidence, assault with a deadly weapon is not a lesser included offense of murder. That’s because the definition of murder doesn’t require that the killing occur through use of a deadly weapon. (Hoffheimer, supra.)
Consider another example. Drug possession is commonly considered a lesser included offense of drug possession for sale (or a similarly named crime, like drug possession with intent to distribute). Simple drug possession often contains the following elements:
A possession-for-sale statute might have the three elements above, with the added element of the defendant’s intent to sell the drug. Because possession for sale contains all the elements of simple possession, it’s a greater offense and simple possession is lesser (or necessarily) included.
Example: Prosecutors can prove that Wallace had several baggies of cocaine in his jacket pocket. They will have no problem establishing that there was enough cocaine to use, that Wallace knew that he had it, and that he knew it was cocaine. If they can show that he intended to sell the drug—perhaps by the fact that he had more cocaine than he could use—then he’ll be on the hook for possession for sale. But if there’s a reasonable possibility that he had the substance simply for his own use, then he is guilty only of simple possession.
A lesser included offense can serve as a fallback for prosecutors—it gives them a way to obtain at least some kind of conviction when the jury might acquit the defendant of a more serious crime. But lesser included offenses can also benefit defendants—see Do juries have to consider lesser included offenses?
As this article might suggest, issues like lesser included and lesser related offenses are complicated. And the law might vary from one state to another, and from state to federal court. These are among the reasons it’s critical to seek explanation and advice from a knowledgeable criminal defense attorney.