Hey Cap'n.
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Just kidding.
The tick boxes and date options do work for me. Example:
On this page
Inmate Search type in the name Jones (no mods, we're not really sleuthing non-suspects, I promise!) and tick the "in custody" box - don't change the date or anything else, just do that and click "search". Notice the very last column that says "housing facility". Now go back and remove the tick from the "in custody" box and search again. You'll notice those that have been released, have a blank spot in the "housing facility" column. If you click on any of those with that blank spot, you'll see the release date listed.
Not that any of that actually matters since he was never there anyway, but the search functions do work and they do list ex-inmates, for whatever reason.