Final answer:
The method that calls itself the primary source for U.S. criminal justice statistics is the Uniform Crime Reporting (UCR) program. The UCR compiles data from law enforcement, while the National Crime Victimization Survey (NCVS) collects information on both reported and unreported crimes.
Step-by-step explanation:
The method of gathering data that promotes itself as "the United States' primary source for criminal justice statistics" is c. Uniform Crime Reporting (UCR). The UCR program, which is run by the Federal Bureau of Investigation (FBI), collects data from approximately 17,000 law enforcement agencies across the country. This data includes comprehensive information from police reports, but it may not account for unreported crimes, which is where the National Crime Victimization Survey (NCVS) provides additional insight. The NCVS is a self-report study administered by the Bureau of Justice Statistics (BJS), which involves asking about 160,000 people annually regarding their experiences with crime, even if not reported to the police. Therefore, the UCR provides detailed official records, while the NCVS captures both reported and unreported crime, giving a broader picture of criminal activity in the United States.