Run scrape.rb and scrape-county.rb to download the raw HTML data. The scripts will sleep between each page download, please don't abuse someone else's servers!
Once that is done, run parse-all.rb to turn the data into a JSON array. The format should be relatively obvious, but please contact me with any questions.
Since the source data is licensed as CC BY-SA 3.0, so is the data here, and the code to generate it. The only real changes are converting from HTML to JSON, and making some of the numeric data a little cleaner to read. Any thanks for the existence of the data should go to insideprison.com.