International Sites
The internet can be an excellent source of criminal justice information, mostly because criminal justice is usually a function of governments which are required to share their information. Here are some sites to get you started. It's by no means a complete list. If you know of other sites that you think would be helpful, please let me know.
Intute: Social Sciences: Policing
"The Social Sciences Government Policy Gateway provides free access to high quality resources on the Internet. Use this site to find papers, reports, articles, educational materials, and organisational websites relating to all aspects of Government policy and public administration. All the resources have been selected by subject specialists to meet the needs of staff, students and researchers in UK higher and further education." (Note - this is a UK based site.)