And here lies the problem, because in reality there is no perfect way of measuring crime, as statistics could be manipulated, especially so that reporting crimes could be influenced by varied factors. For example, as commonly depicted in crime movies – be they fictional or documentary – police, classically, under-reports or over reports crime due to any or convergence of the following reasons: political pressures, need for greater resources, image building, sets of beliefs or values, training and expertise, etc. It is in this context that the two primary crime data sources in the US: the Uniform Crime Reports (UCR) and the National Crime Victimization Survey (NCVS) are to be compared and analyzed focusing on their specific characteristics, purposes and methodology. Much of the basic information regarding the UCR and NCVS are mainly taken from government documents, while insights are taken from books and peer-reviewed articles.The UCR, a crime reporting program that began in 1929 under the direct supervision of the Federal Bureau of Investigation (FBI) has been collecting crime and arrest data from the monthly summary crime reports voluntarily submitted by the 17,000 out of the 18,000 police agencies in the US nationwide for 69 years now focusing mainly on ‘Index crimes’ such as, in hierarchical order: murder and non-negligent manslaughter, forcible rape, robbery, aggravated assault, burglary, larceny-theft, motor vehicle theft, and arson – incidents which due to their seriousness, witnesses instantly knew that these are criminal acts prompting them to most likely report these incidents to police authorities. Thus, the crime data UCR possesses are only reported crimes. (Maltz, 1999, p.1) Aside from crime counts and trends, crime data from UCR also includes data on the following: crimes that are already cleared.