Bureau of Justice Statistics (BJS) is the primary statistical agency of the Department of Justice.The mission of BJS is to collect, analyze, publish, and disseminate information on crime, criminal offenders, victims of crime, and the operation of justice systems at all levels of government.
The FBI's Crime Data Explorer (CDE) aims to provide transparency, create easier access, and expand awareness of criminal, and noncriminal, law enforcement data sharing; improve accountability for law enforcement; and provide a foundation to help shape public policy with the result of a safer nation.
National statistics on arrests and seizures, links to national studies and publications, and state fact sheets collected by the United States Drug Enforcement Agency (DEA).
The National Archive of Criminal Justice Data (NACJD) is the place to discover, access, and analyze data on crime and justice. NACJD hosts several large-scale datasets, including the National Crime Victimization Survey (NCVS), the FBI's Uniform Crime Reports (UCR), the FBI's National Incident-Based Reporting System (NIBRS), and the Project on Human Development in Chicago Neighborhoods (PHDCN).
The National Center for Juvenile Justice is a private non-profit research organization devoted to understanding, prevention and control of child and family justice. Publications provided on the website include statistical factsheets and reports, such as the annual Juvenile Arrests bulletin.
From the Office of Juvenile Justice & Delinquincy Prevention, the Statistical Briefing Book contains publications, data sets, & analysis tools about juvenile crime and victimization and youth involved in the juvenile justice system.
The Pennsylvania Uniform Crime Reporting (UCR) Program serves as the state repository for the collection of crime statistics and its primary objective is to generate reliable information for use in law enforcement administration, operation, and management.
United Nations Office on Drugs and Crime (UNODC) research constitutes the key global authority in the fields of drugs and crime, providing high-quality, essential evidence to inform policy-making and valuable sources of knowledge in drugs and crime domains
he World Prison Brief (WPB) is a unique database that provides free access to information about prison systems throughout the world. Country information is updated on a monthly basis, using data largely derived from governmental or other official sources.
If you are using sites other than the ones above, use credible sources. In the field of criminal justice you should be looking at sites that have the domain of .gov or .org for the most reliable information.