"In the UCR Program, a law enforcement agency reports that an offense is cleared by arrest, or solved for crime reporting purposes, when three specific conditions have been met. The three conditions are that at least one person has been:
"• Charged with the commission of the offense.
"• Turned over to the court for prosecution (whether following arrest, court summons, or police notice).
"In its clearance calculations, the UCR Program counts the number of offenses that are cleared, not the number of persons arrested. The arrest of one person may clear several crimes, and the arrest of many persons may clear only one offense. In addition, some clearances that an agency records in a particular calendar year, such as 2020, may pertain to offenses that occurred in previous years.
"Cleared by exceptional means
"In certain situations, elements beyond law enforcement’s control prevent the agency from arresting and formally charging the offender. When this occurs, the agency can clear the offense exceptionally. Law enforcement agencies must meet the following four conditions in order to clear an offense by exceptional means. The agency must have:
"• Identified the offender.
"• Gathered enough evidence to support an arrest, make a charge, and turn over the offender to the court for prosecution.
"• Identified the offender’s exact location so that the suspect could be taken into custody immediately.
"• Encountered a circumstance outside the control of law enforcement that prohibits the agency from arresting, charging, and prosecuting the offender.
"Examples of exceptional clearances include, but are not limited to, the death of the offender (e.g., suicide or justifiably killed by police or citizen); the victim’s refusal to cooperate with the prosecution after the offender has been identified; or the denial of extradition because the offender committed a crime in another jurisdiction and is being prosecuted for that offense. In the UCR Program, the recovery of property alone does not clear an offense."
FBI Uniform Crime Report. Crime in the United States 2020 - Arrests and Arrest Table: Arrests for Drug Abuse Violations. Washington, DC: US Dept. of Justice, September 2021.