While I sympathize with your friends accident, having had to argue in court against a fraudulent ticket...the State AUTOMATICALLY assumes the radar is correct and accurate...it is up to you BEFORE arriving at the Court, to have the evidence to disprove the radar...you CANNOT try to get this info at time of hearing, or they toss your a$$ and find against you..
Just another example of how the State has rigged trials against the populace!
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.