Yes you can fight a speeding ticket, even if it has been done using laser!
When you look at the people who try to fight a ticket in traffic court, you will hear the same claims over and over with the same result. They state it wasn't them, or perhaps it was but they had a good reason. Maybe their speedometer is off. Perhaps they beg for mercy. Perhaps they have a wonderful driving record. The judge will listen for about 30 seconds, reduce their fine for having showed up, and move on. The ticket is still on their record.
To fight your ticket, you must first write to the police person who gave you a ticket and request the following: A copy of his notes/journal for the 24 hour period prior to your ticket (including calibration records if they are kept elsewhere), a copy of the back of your ticket front and back, and the make and model of the unit used.
Sometimes the police department will say you don't have right to these things, however if you state your request is a part of "discovery" for court, they must comply. You may have to escalate it to get the information. You can ask for an extension of your court date if the police department or sheriff department is twiddling their thumbs.
The notes/journal of the past 24 hours will show just how many traffic stops this cop has made. They aren't allowed to put up speed traps, so maybe it's relevant, maybe not. It will also show when the unit was last calibrated before tagging you. This will tie into the manual.
The copy of your ticket, front and back, will show you what the cop wrote to keep in his head what he observed. Forewarned is forearmed.
The make and model of the laser unit is INCREDIBLY important. You will then somehow try to get a copy of the full manual for the same unit. Either you can order it from the manufacturer, or I once called the police station library and they faxed it to me... All of it. It will probably cost you anywhere from $25 to $50 for a copy, but will be well worth it. Get creative if you get told you can't have a copy. Of course they don't want you to have one, otherwise people might actually find that most speeding tickets could potentially be based on faulty operation.
Read the entire manual. Somewhere in there it will be a paragraph that states if you are NOT trained at the manufacturer training facility you run the risk of getting spurious readings. This is so important, you will highlight it. You will also highlight anything else that talks about spurious readings and calibration. At your hearing one of the questions you will ask is who trained you on this specific unit (or what training did you receive on this specific unit). Most likely he will say some other officer trained him. When he answers your question, you will state you have the operating manual for the unit (you need to ask him what unit it is even though you already know prior to this). You will then ask, "So you were never trained at XYZ" with XYZ being the exact name the manufacturer uses for their training facility. Read your highlighted points as you make them, always stating in the manual on page x under the title y. It gets everything on the record.
The manual will also say that after each time the unit is used, it must be re-calibrated, or at what intervals calibration must take place. This is important because you will have the calibration records. You can also go one step further and ask for all maintenance records of the unit and again cross check what you have received with the manual. Usually these units are way behind on regular maintenance.
The other thing that your manual will tell you is that when there is a larger vehicle nearby, the laser will pick up that vehicle instead of yours despite the laser pointing at your vehicle. This is key. Was there a large SUV near you? Was there a semi truck? A panel van? Again, you ask the cop this, and he will say he doesn't remember (if he is honest). If he says there was not, ask how he can be sure. Refer to the page in the manual and read it aloud.
Also, was there a similar car near you? For example, if you drive a Honda Civic, was there another one near you that happen to notice passing you just prior to getting pulled over?
All this does is put enough doubt on the matter. Perhaps he tagged one car, but pulled over another. Also, the manual shows that it is possible the reading was not accurate in the first place.
Some other questions you can ask: Was the cop stationary or moving at the time? What portion of your vehicle did he tag you? (If you have smokey covers on your license plate, it wouldn't work accurately. If your car is black, it doesn't work accurately.) When did he come on his shift? When was his last break before he tagged you? How many people did he pull over in the hour prior to pulling you over?
As a side note, the last ticket I fought this way was the first one to get kicked out completely in five years. I asked all my questions, then stated I had the manual and disproved everything the cop said. Another little tip: The judge will probably keep the manual, so if you want it, make a copy of it.
Good luck in court!