Neither of these are serious offenses.
Here's the problem with your whole, "Let's lock up illegals for littering" strategy. This means an illegal is going to be taking up a jail cell until the Feds get around to deporting him. (They already have 1.5 million people slated for deportation whose home countries don't want them back.) This means that the local authorities are going to have to make decisions about who to let out to make a cell for that illegal.
Maybe they let out the more dangerous criminal until his trial comes up.