
Quoting
DavidForthoffer
You could ask the officer to submit evidence that the speedometer on his vehicle was calibrated properly.
You would then object in any of the following situations.
a) It was neither an original nor a certified copy.
b) It was not signed.
c) It was not filled out properly.
d) It was prepared by a non-governmental agency (which would mean that, as a business record, the author or custodian must appear and testify to its authenticity).
Since you requested discovery and he did not submit the speedometer calibration certificate, maybe that means he could not submit it during trial!
Supposing that he was not able to submit a valid speedometer calibration, you could then argue he could not prove the speed he was traveling.
I know of one California judge who would dismiss tickets when a speedometer calibration was not submitted.
You could also ask him detailed questions about how long he paced you, and how close he was when he did. Ask his maximum speed when approaching you, or whether he braked. Sometimes they offer physically impossible scenarios, so if you know the physics (acceleration or deceleration formulas) you can point that out.