My county has some old criminal cases where a judgment has been entered and the defendant was to pay his fine and/or restitution in monthly payments. Of course, they have not been paid. What can I do to try to collect this money? Does a capias pro fine need to be issued? If a capias pro fine is issued and the defendant is arrested, what can happen to the defendant after that?

A capias pro fine should be issued. See CCP Art. 43.03.

Shane: You might also check with those Office of Court Administration guys that are working on increasing collections in the state; Jim Lehman is the man who spoke on collections at our Elected in December, and his number at OCA is 512-463-1625....