Homicide Closure Rates - 2002-2011
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A Note on Homicide Closure Rates and General Homicide Statistics
Information on the agency’s annual homicide clearance (closure) rate is published each year in the Metropolitan Police Department’s (MPD) Annual Report.
The MPD’s homicide clearance rate is calculated, as it is by most police departments in the country, using the Uniform Crime Reporting (UCR) guidelines established by the FBI in the 1930s. These guidelines are the national standard for reporting several categories of crime data, including homicide clearance rates. Nearly 17,000 law enforcement agencies across the United States provide data to the FBI under its UCR program.
Calculation of Homicide Clearance Rate According to UCR Guidelines
Under UCR guidelines, the clearance rate is calculated by dividing the total number of homicide cases closed in a calendar year by the total number of homicides that occurred in that year. The cases closed can be for homicides that occurred in the current year or in the prior years. In other words, some clearances that an agency records in a particular calendar year may pertain to offenses that occurred in previous years. The UCR program measures all of the work that an agency exhausts in closing cases.
Note on Calculating the Annual Number of Homicides
UCR guidelines require that a homicide be counted during the year in which the case is ruled a homicide. In other words, law enforcement agencies are required to count homicide cases resulting from assaults that occurred in previous years. For example, if a person is shot in 2008, but dies in 2011 due to his or her original injuries, this would be counted as a homicide in 2011. In recent years, the department has carried as many as 10 such homicides in a given year.
UCR Homicide Closure Criteria
Law enforcement agencies can clear, or “close,” offenses in one of two ways, either by arrest or by exceptional means. To clear an offense within the UCR Program’s guidelines, the agency must adhere to specific criteria.
Cleared by Arrest
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 (i) arrested; (ii) charged with the commission of the offense; and (iii) turned over to the court for prosecution.
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 (i) identified the offender; (ii) gathered enough evidence to support an arrest, charge, and prosecution; (iii) identified the offender’s location; and (iv) encountered a circumstance outside the control of law enforcement that prohibits the agency from arresting, charging, and prosecuting the offender. One example would be the death of the offender, such as a murder-suicide, where the offender was known to have committed a murder and subsequently committed suicide before being charged and prosecuted.