Lesser included offense

A lesser included offense, in criminal law, is a crime for which all of the elements necessary to impose liability are also elements found in a more serious crime. It is also used in non-criminal violations of law, such as certain classes of traffic offenses.

For example, the common law crime of larceny requires the taking and carrying away of tangible property from another person, with the intent to permanently deprive the owner of that property. Robbery, under the common law, requires all of the same elements, plus the use of force or intimidation to accomplish the taking. Therefore, larceny is a lesser included offense in the offense of robbery, as every robbery includes a larceny as part of the crime. Assault is also a lesser included offense of robbery, just as battery is necessarily a lesser included offense to murder, and false imprisonment is usually a lesser included offense to kidnapping.

In the case of traffic offenses, serious misconduct while operating a motor vehicle can result in a charge of reckless driving, which could, in egregious cases, be punishable as a misdemeanor by imprisonment as well as a potential fine. However, if the person charged proves to the court their actions were not as serious to constitute recklessness, may in some jurisdictions qualify as the lesser-included offense of improper driving, which is not a crime and is only punishable by a fine.

Merger doctrine

Under the merger doctrine as this term is used in criminal law, lesser included offenses generally merge into the greater offense. Therefore, a person who commits a robbery can not be convicted of both the robbery and the larceny that was part of it.

Solicitation to commit a crime and attempt to commit a crime, although not strictly speaking lesser included offenses, merge into the completed crime. As an important exception, the crime of conspiracy does not merge into the completed crime.

Use in jury proceedings

In criminal jury trials, the court is permitted (but not required) to instruct jurors that they can find the defendant guilty of the most serious crime charged, or of a lesser included offense of that crime (in English law, this is termed an alternative verdict).

In murder cases, however, where a convicted defendant may face capital punishment, the United States Supreme Court has held that the court must instruct the jury that they may find the defendant guilty of a lesser included offense such as voluntary manslaughter. The reasoning for this ruling is that jurors, given the options of convicting a less culpable killer or letting him go free, might opt to convict of a more serious crime than the facts warrant. Therefore, they must have at least one option that falls in between these extremes.