if someone is found guilty for trespassing on someone else property such as throwing trash on other's property. What will most likely be judge decisions if he is found guilty for it?
The sentences for different types of convictions vary from state to state. You'd have to look up the violation in a particular state's code of law.
For example, here's the law for Texas:
http://www.tidrc.org/Laws.htm
For California: http://www.donttrashcalifornia.info/pdf/Frequently_Asked_Questions.pdf
And you can look up others in Google.
"littering penalty _____" <~~put state in the blank
=)