What are they?
Government agencies are often required to produce reports on a wide variety of topics. In criminal justice these might be the evaluation of a program or department, and overview of an area of research, or a variety of other topics.
How do I find them?
The best way to find these kinds of sources is to go straight to the government agencies themselves or use a service like NCJRS. Try using the word "report" when you search for a title if you have trouble, it can be surprisingly effective.
How do I know I've found one?
This is what generally trips students up. What does a "government report" look like? Unfortunately there is no perfect clear cut answer, but generally there are some common characteristics: