Answer:
Uniform Crime Report( UCR) is a collection of the information of criminal activities in the United States published by the Federal Bureau of Investigation (FBI).
Explanation:
The uniform crime is compiled from the provided resources and data of there relatively smaller security agencies.
So basically, other security agencies like the police, homeland security, national security agency, united state intelligence community, etc compile data and reports based on arrest and other criminal activities.
This reports are then forwarded to the Federal Bureau of Investigation who are obliged with the core responsibility of publishing the uniform crime report.
The validity concern with this method of measuring crime is basically based on the fact it omits crime not reported to the police and if there is a change in the local law, it can cause information spikes which consequentially cause the data to be slow in coming out.
