NJ doesn't discriminate about police officers in a family anymore. As a matter of fact, my brother, who is a police officer was called to jury duty and was picked for the jury!
I was on a jury once, and dang, I tried to use the police officer thing (father, brother, uncle) and not only was I picked, but I was on the jury with the wife of a police officer (who's husband was currently running for Sherif!) :lol:
You should be able to be excused if you are the primary care giver. You can call, write or show up the first day and tell the judge why you wouldn't be able to serve: It would be a hardship on your family.