I've seen this repeated in discussion forums but haven't been able to find a source. The only reference I can find about his father's occupation is that he is retired military man. Can you point me to a source?
I googled “magistrate judge george zimmerman” and got 373,000 results. His dad is Robert J Zimmerman, a former Orange County magistrate judge. Can you say “good ol’ boys club”?
Here’s one source, you’ll have to look up the rest yourself.