Once held to reflect accurately the incidence of crime in society, first produced in France in 1827 and regularly for England and Wales since 1837, such statistics—like all official statistics—are now interpreted with caution. Criminal statistics are based on notifiable (triable by jury) recorded offences, and can be drawn from aggregate data recorded by official agencies such as the police and courts, but also from criminological research studies. Limitations have been confirmed by the national British Crime Surveys (begun in 1982 and annual since 2000) which have produced data on typically unreported and hidden crime such as vandalism. Even victim surveys can have difficulty eliciting data about some crimes—such as rape and sexual attack. Localized surveys suggest that both routinely compiled criminal statistics and national survey data seriously under-record crime generally and crimes such as rape in particular.
Most sociologists recognize that the criminal statistics are the product of a complex process. Society must first define a behaviour as criminal, but the definition of a criminal act can change over time, and between jurisdictions. To enter the statistics a crime must be reported and recorded, but the public do not report all offences, while changes in police procedure, or simple human error, can mean no record is made. The outcome of a court case, and hence the statistical recording of a conviction or otherwise, also depends upon a complex mix of ingredients. Some would argue, therefore, that criminal statistics are less a picture of the incidence of crime than an indicator of what the authorities regard as the most important offences, what the police actually find it manageable to police, and what kind of offence the court system tends to process with convictions resulting. Nevertheless, after a period of criticism and distrust, use of criminal statistics has been regaining broad acceptance. See also crime-rate; official statistics.
http://www.statistics.gov.uk/CCI/nscl.asp?ID=5685 Reports on official statistics on crime in the UK.
http://www.ojp.usdoj.gov/bjs/ The US Department of Justice.