Absolutely, and I have...twice.

Unless there are some union provisions to the contrary you are not obligated to give someone an unplanned, spur-of-the-moment LOA because they somehow ended up in jail. It's not like jury or military duty...you can simply fire them for not coming to work after X number of days (like anyone else who no-showed).

There is a certain segment of society who have a bail-bondsmen on speed-dial, but I always held my employees to a higher standard of behavior. You can also easily fire someone (caveat for possible union provisions) who brings public discredit on the company...murder, rape, kidnapping, child sex abuse, etc all meet that standard in the eyes of a reasonable person. You can expect your employees to conduct their private lives in such a manner as to avoid these sorts of legal entanglements. Private behavior is their business but once it hits the police blotter and local news it's no longer private.