Justice Information Center
Information on the U.S. criminal justice system, covering subjects including juvenile crime, law enforcement, corrections, and crime prevention, from the National Criminal Justice Reference Service. http://www.ncjrs.org/
Inter-University Consortium for Political and Social Research
Provides access to an extensive collection of downloadable data. While some data is only available to individuals from member institutions, an extensive collection of criminal justice data, election data, and data from the General Social Surveys is available to the public from this site. http://www.icpsr.umich.edu/