The British Crime Survey (BCS) provides an important source of information about levels of crime, public attitudes to crime and other related issues. The results play an important role in informing Home Office policy. The BCS measures the amount of crime in England and Wales by asking people about crimes they have experienced in the last year. This includes crimes not reported to the police, so it is an important alternative to police records. Victims do not report crime for various reasons, and without the BCS there would be no official source of information on these unreported crimes. Because members of the public are asked directly about their experiences, the survey also provides a consistent measure of crime that is unaffected by the extent to which crimes are reported to the police, or by changes in the criteria used by the police when recording crime. The survey also helps to identify those most at risk of different types of crime, and this helps in the planning of crime prevention programs. The BCS also examines people's attitudes to crime, such as how much they fear crime and what measures they take to avoid it. The survey also covers attitudes to the Criminal Justice System (CJS), including the police and the courts, and has also been successful at developing special measures to estimate the extent of domestic violence, stalking and sexual victimization, which are probably the least reported to the police, but among the most serious of crimes in their impact on victims.