That makes sense, and seems to be a good use for them.
But then we get into questions like how can an officer write a ticket saying he witnessed a car driving X mph when he really didn't? Isn't that lying on a legal document*?
And wouldn't both the lidar officer & the ticket agent have to appear in court to testify against the driver?
*(don't get me started)
Yes, both the laser user and the chase car cop are required to appear, otherwise you can object everything as hearsay.
Now there are very few small town judges who actually follow the law, and refuse to toss the case, and appealing is cost prohibitive, so have the law and caselaw printed (there is a ton of it out there on this very specific topic) to educate the judge. It is also beneficial to have the operations manual for the laser unit with you where the manufacturer states limitations.
Also, anything over 1000 feet when laser is used is questionable due to the sighting apparatus and a hand-held laser unit not being accurate at that range. they could be sweeping cars over a several yard range both next to you, in front and behind you. There is no visible laser marks on the target vehicles to verify that they are on target. Many have FOIA'd cops handgun shooting qualifications to show how inaccurate they are at 20 feet, now imagine something 10 times heavier being held steady without a tripod with a zero magnification sight, and over 300 yards.
The LTI 20/20 (the Geico gun) was proven to show stationary objects traveling at speed due to slight movement of the unit while targeting. A defense attorney showed a courtroom wall to be moving in excess of 30 MPH during a trial.