Statutes governing this must vary from state to state. In PA, the date of last calibration must be included in the citation (I’m pretty sure this is the case in MD and VA too, but I don’t know that for an absolute fact.) Without it, the citizen is considered to be denied the right to prepare a defense and the citation is thrown out. It’s a pretty standard procedure (here in PA).
BTW- for what it’s worth, I’ve racked up a few violations in my younger days (speeding, incomplete stop), and I’ve been guilty every time. As hard as that may have been to admit.
Interesting point. Red-light cameras may not even be permitted in New Jersey -- a state Supreme Court ruling from 10-15 years ago outlawed unmanned speed radar traps. I think the rationale was that anyone accused of a criminal or traffic offense has to be cited by a person, not a machine.