Dashcam video with GPS speed imprint - court date soon...

**erkme73** · 02-17-2007, 05:41 PM

This is my first post at this forum - go easy on me...

Does anyone know of any precedent in US (traffic) court where a defendant was able to challenge a laser-gun citation with GPS speed (on video)? I've read the horrible outcome of 96transam, but I think my situation is quite different.

Here's where I'm going with this:

I have a dash-cam and DVR that records my windshield view whenever my vehicle is in motion. Using a video overlay box, I imprint the GPS heading and speed on the recorded video. One of the reasons for the entire setup (among others) was to be able to challenge any law enforcement claims of speeding. I've only had two speeding tickets during my 20+ driving year career - so don't get any ideas

As (bad) luck would have it, just two months after the installation of the camera/GPS package, I was pulled over by our my local (Florida, County) Sheriff. He claimed I was driving 72 MPH in a 55 MPH zone. I quickly reviewed the video with the officer (who commented how 'cool' my system was) - and found that my GPS recorded speed was between 68.3 and 68.5 MPH. The officer insisted that he "tested" his laser gun every morning, and refused to alter the citation.

Mind you, I WAS speeding - and I do not contest that. However, the 4MPH difference between 13MPH and 17MPH is the difference between a minor and MAJOR speeding violation - something over which the insurance companies sit up and take notice. 15+MPH is MAJOR.

I will contest the ticket in court, and I intend on brining my video with me for the judge to see for himself. Obviously there will be certification/alteration issues, but assuming the judge allows the video, I will need to provide evidence that GPS technology is accurate - at least as accurate (if not more) than any stationary Doppler based equipment (laser/radar).

I've searched Google high and low looking for something like this, but apparently, I'm the only anal/paranoid person who's every a) installed such a system, and b) tried to prove laser isn't as accurate as GPS.

That's where I need mp3Car's help. Does anyone how to find out what the most effective way is to verify accuracy?

I'm using an older Gamin eTrex 12 channel hand held receiver. I also have a SIRF III bluetooth GPS receiver that I use with my DELL x51v - and when compared side to side, they're dead on - to the tenth of a mile.

Short of hiring an off-duty cop to validate the accuracy, I really don't know what else to do.

Would be open to any ideas.

-------------------------------------
ADDED 8/27/07
Now that the court date is over, I am not concerned about the state finding me. I'm now openly hosting the video here:

http://www.youtube.com/watch?v=s5se8n5XSuY
-------------------------------------

You can see the cop at 08:09:09 on the right side of the road. If anyone wants to 'host' this video for me, it would help. My FTP server is constantly under hack attacks, and I've filtered allowable IP addresses pretty heavily. I'd upload it here, but asf files are not permitted.

You may need to install an audio code for your video player to be able to play correctly.

**MobiTekLink** · 02-18-2007, 06:23 PM

This is pretty cool, as with any new technology you are gonna have to prove that the speeds are accurate within an margin of error; I'd suggest you take a video of the speedometer compared with the GPS on the same screen (if its possible) as to diminish doubt over doctoring.
It also comes down to the judge and how tech friendly he is.
Unfortunately, you are gonna challenge a proven technology and the training of a so called "sheriff" against you and your new toy; so thats' a given, the good thing is that OJ Simpson is free 'cos there was no video of him murdering the two people, so video always helps at least to cast a shadow of a doubt which is all that you need.
Good luck,,, haha

**erkme73** · 02-18-2007, 07:11 PM

I'm back-peddling already... I don't think I'll use the video, because all the judge will do is accept it as a confession that I was going 68. While that's an improvement, it doesn't address the core issue - which is that LIDAR used by PSCO, at least in this case, is off by a substantial amount.

Garmin's own website lists my receiver's velocity accuracy to +/- 0.1 knots (0.1MPH). All available laser cameras insure an accuracy of no more than +/- 1.0MPH (according to guysoflidar.com - who list the specs on all current guns).

So, I'm going to approach this from a chain of evidence stand point, and dispute that I was going 72MPH. I won't testify that I was or wasn't speeding - as that is not the charge. The charge is that I was doing 72MPH.

Here's a snapshot of the video...

**pate60** · 02-18-2007, 07:37 PM

*shakes my finger at you* good luck matey, dont forget to let us know how you go.

**Wiredwrx** · 02-18-2007, 07:42 PM

Originally Posted by erkme73

I'm back-peddling already... I don't think I'll use the video, because all the judge will do is accept it as a confession that I was going 68. While that's an improvement, it doesn't address the core issue - which is that LIDAR used by PSCO, at least in this case, is off by a substantial amount.

Garmin's own website lists my receiver's velocity accuracy to +/- 0.1 knots (0.1MPH). All available laser cameras insure an accuracy of no more than +/- 1.0MPH (according to guysoflidar.com - who list the specs on all current guns).

So, I'm going to approach this from a chain of evidence stand point, and dispute that I was going 72MPH. I won't testify that I was or wasn't speeding - as that is not the charge. The charge is that I was doing 72MPH.

I would avoid using the GPS info in court. In a way, it is an admission, and that is not necessarily the right way to go.

While the officer may have "calibrated" his gun that morning, you should make him prove it. THey should keep a log. Of course, the log can always be doctored, but you never know.

Next, and this is where the technical stuff comes in, MOST officers "calibrate" thier guns using the gun itself. Besically, the radar gun comes with a self test ot sorts. You move a switch, or press and button, and the radar gun does a selg check. THIS IS NOT A PROPER CALIBRATION. While the gun may not know it, because for whatever reason, the "part" in the gun is working right, Iit could be out of specs, and return in anvalid reading. The only 100 percent proper calibration technique is WITH A TUNING FORK. And, the tuning fork must be certified calibrated on a regular bassis, for it to be 100 percent accurate. ALL RADAR GUN MANUFACTURERS STATE THIS. Even if the officer clains he used a tuning fork, which I HIGHLY DOUBT, you can attack the accuracy of the tuning fork, because it has been riding in his cop car/motorcycle for who knows how long, bumps, chases, potholes, who knows what else.

http://www.nolo.com/article.cfm/Obje...4/308/214/QNA/

Also, read the post by John D Armond here http://williambader.com/tickets.html He has lots of good ideas. I would suggest you do them.

Michael

**Wiredwrx** · 02-18-2007, 07:43 PM

Originally Posted by erkme73

I'm back-peddling already... I don't think I'll use the video, because all the judge will do is accept it as a confession that I was going 68. While that's an improvement, it doesn't address the core issue - which is that LIDAR used by PSCO, at least in this case, is off by a substantial amount.

Garmin's own website lists my receiver's velocity accuracy to +/- 0.1 knots (0.1MPH). All available laser cameras insure an accuracy of no more than +/- 1.0MPH (according to guysoflidar.com - who list the specs on all current guns).

So, I'm going to approach this from a chain of evidence stand point, and dispute that I was going 72MPH. I won't testify that I was or wasn't speeding - as that is not the charge. The charge is that I was doing 72MPH.

Here's a snapshot of the video...

Didn't you see the cop there waiting? Also, can you remove the speed? Perhaps you can use the video to prove you were not going faster than the regular flow of traffic.

Michael

**erkme73** · 02-18-2007, 08:10 PM

I saw him in the video! But not on the side of the road. Quite frankly, I drive in the upper 60's every day - along with other marked police cars that are on their way to work. Not an excuse, of course, but that particular area has 6 lanes of traffic, few side streets, and everyone does at least 10 over. Won't use that to my defense - but it helps explain why I wasn't on higher alert for cops. In fact, in the video, I continue to drive 68.3 to 68.5 MPH for at least another 1/4 mile - at which point I finally saw the lights behind me.

woops...

**kno3** · 02-18-2007, 08:15 PM

what baffles me is that insurance companies have not jumped on the video record system- it makes a LOT of sense to have a DVR recording with all the "black box" info for cars. Would it not be indisputable evidence in any accident investigation? Blows my mind they can spend BILLIONS on fraud claims, but wo'nt install a cheap dvr system in their client's cars.

**NiSlo** · 02-18-2007, 08:16 PM

Originally Posted by erkme73

I quickly reviewed the video with the officer (who commented how 'cool' my system was) - and found that my GPS recorded speed was between 68.3 and 68.5 MPH.

Do they record all traffic stops over there? If they do, then wouldn't it have recorded you reveiwing the tape with the officer and already admitting that the system says you were doing 68.3 and 68.5? If that's the case then wouldn't you be better off sticking to your original plan and trying to have the fine reduced?

**DJiK** · 02-18-2007, 08:26 PM

Originally Posted by erkme73

Does anyone know of any precedent in US (traffic) court where a defendant was able to challenge a laser-gun citation...?

Originally Posted by Wiredwrx

While the officer may have "calibrated" his gun that morning, you should make him prove it. THey should keep a log. Of course, the log can always be doctored, but you never know.

Next, and this is where the technical stuff comes in, MOST officers "calibrate" thier guns using the gun itself. Besically, the radar gun comes with a self test ot sorts. You move a switch, or press and button, and the radar gun does a selg check. THIS IS NOT A PROPER CALIBRATION. While the gun may not know it, because for whatever reason, the "part" in the gun is working right, Iit could be out of specs, and return in anvalid reading. The only 100 percent proper calibration technique is WITH A TUNING FORK. And, the tuning fork must be certified calibrated on a regular bassis, for it to be 100 percent accurate. ALL RADAR GUN MANUFACTURERS STATE THIS. Even if the officer clains he used a tuning fork, which I HIGHLY DOUBT, you can attack the accuracy of the tuning fork, because it has been riding in his cop car/motorcycle for who knows how long, bumps, chases, potholes, who knows what else.

Michael, do police officers need to calibrate a Laser Gun with a tuning fork too? Or does that only apply to radar (radio) guns?