I don't think this will help much, but it might give me some info on radar 'guns'.
Was the radar gun in her car? If so, is it not like a laser gun, where the officer has to target and then 'shoot' said vehicle? A silly one, but how do you know that 42 was your speed on the gun? (Maybe she was catching everyone at 42) I bring that up simply because I have seen an officer try and fine me when the power to the laser gun was disconnected and he couldn't show me my speed!
Here in RSA, I have hardly seen radar guns, they seemed to go out of fashion with Noah's ark. I have come across stand alone ones twice in recent years, but these worked with photo only.