Use this guide as you would a map; it'll help you locate the information you need.
Image Source: by Kwekubo. Street Map of Dublin. CC-BY-SA-2.0. Wikimedia Commons.
Criminal Justice is the system of practices and institutions of governments directed at upholding social control, deterring and mitigating crime, or sanctioning those who violate laws with criminal penalties and rehabilitation efforts."
When searching for criminal justice information, a variety of different databases should be used. You'll find databases that'll provide you with journal articles on criminal justice topics under the articles tab.
Also, one should take advantage of a broad array of information: background information, articles, books, ebooks, and statistical resources.
Image Source: CC BY-SA 3.0. Wikimedia Commons.