The courthouse was the building of the Methodist Church in Monrovia, California. Much, if not all, of the religious symbolism was digitally erased by early CGI.
In the early stages of development, the show was called "Security Fences". As the crime aspect grew to become the center focus, and Rome became less secure, producers decided that the show should be renamed "Picket Fences".
In the pilot episode, when Jill (Kathy Baker) is giving advice to Zach (Adam Wylie) to help him with his shy bladder, she tells him to think about other things to distract him. One thing she mentions specifically is that he should think of his favorite movie star, Arnold Schwarzenegger. One of Adam Wylie's first roles was only two years prior to this episode, in Kindergarten Cop (1990) wherein he shared screen time with Arnold Schwarzenegger.
There are two communities named Rome in Wisconsin. One is an Adams County resort town with a population of around twenty-five hundred, and the other is a Jefferson County unincorporated town with a population of under six hundred. Neither Rome is in proximity to Green Bay. Hogan County, the location of Rome is fictional (there is no county named Hogan in any of the fifty states).