Official statistics

Official statistics on crime are used extensively by sociologists as indicators of the amount &type of crime and the background of offenders, even though they cannot represent the "real" rate of crime. 

Much crime is invisible, because most crime is under-reported for a number of reasons, including:
 • victims do not know a crime has been committed upon them 

• victims make the decision not to report a crime because of embarrassment or trivial nature of the crime.
• decisions by the police to deal with crime unofficially rather than officially 
• difficulty of detecting some crimes…