This is just a broad look at data sources for politics--
Bureau of Justice Statistics - Browse by topic, or do a quick search, for national statistics that relate to crime and criminal justice. Use different terms if you can't find what you need. For instance, there are no statistics for "domestic violence", but there are for "intimate partner violence."
Census Bureau
Data.gov - For statistics of the more than 70 agencies in the U S Federal Government.
European Commission Statistics
Statistical Sites on the World Wide Web - Posted by the US Department of Labor, Bureau of Labor Statistics, this offers a quick guide to national and international governmental and organizational sites.
United Nations Statistics Division
World Bank Open Data