True. However, it is reasonable to assume that there is some basis for the noted speed. If not, so be it.
Either way, the judge will pay heed to what the cop say unless there is inctrovertible evidence to the contrary. If that evidence doesn't exist, what's on the ticket is what will be judged. If 120 is the number judged, a lawyer is MORE than needed.
Again, best of luck, and be sure to do everything you can to seek expert legal help and prepare for the court.
PS: I don't know have VA is, but in MD, if the radar operator doesn't show to court, the state has no witness and the ticket is dismissed. For that reason, I always postpone the court date as long as possible. The theory is that the longer you can postpone the date, the more likely the officer won't be available to make the date (no longer in service, transferred to another area/department/etc, or otherwise unable to make the date). I've had at least two tickets simply "vanish" using this method.