Great question, I'll bet a lot of people want to know the answer to this. For basic crime and demographic stats, go to http://www.epodunk.com. It works everywhere. For more detailed information, check with your local police department.
Also, here is a link to Megan's Law Go to the bottom of the pages, there is the link to enter into the site.. http://www.meganslaw.ca.gov/
Hope this helps.
Click on the link that is provided and then scroll down to the map of Riverside. Click on the West quadrant and the stats pop up and are sorted by a code. The code is given in the legend. It is really cool and updated monthly. Hope this helps.