RE: Police laser guns can be wrong
Monday 20th March 2006
LTI 20-20 UltralyteHandheld speed measuring guns, as used by the police up and down the country, could be inaccurate, according to a Home Office official. The admission was wrung from Geoffrey Biddulph, Head of the Road Crime Section in the UK Home Office, who admitted in a newspaper letter that the laser-based technology is not infallible.
Police laser guns can be wrong
Court hears of speed devices' inaccuracy
LTI 20-20 Ultralyte
Tests undertaken at the manufacturer's direction have shown that, under certain circumstances, one of the guns, the popular LTI 20-20 Ultralyte model, has shown brick walls travelling at 44mph, an empty road 33mph, a parked car at 22mph, and a slow-moving bicycle at 66mph.
The issue arose following a case of a motorist who was at first accused of driving at 106mph on the M6 toll rod. Eventually, Stoke Magistrates Court acquitted the man, Stewart Walker, on the grounds that the speed gun could have been measuring the car that was overtaking him, a situation that a police officer under oath admitted was possible.
As a result of the case, Safe Speed founder Paul Smith called for the recall of the devices and said that the Home Office should "make arrangements to compensate those convicted or fined on the basis of unreliable evidence."
Discussion
With reference to a thread last year, it seems to clear up the misconception that the M6 is a private road, and you cant be dont for speeding..........
Having driven on it, I can see the tempetation, after all the frustration of the M6 itself, to be let loose on a clear open stretch of motorway......
Having driven on it, I can see the tempetation, after all the frustration of the M6 itself, to be let loose on a clear open stretch of motorway......
It should also be noted that Stewart Walker is a PHer, who asked for help on the S,P and L forum. I have been giving him a hand for the last few months on how to deal with the CPS and trial from the times I have defended myself in court, as he couldnt afford the solicitors fees.
Not asking for credit myself, but it must be said that this is all thanks to Pistonheads, and proof that as a community if we all pull together, we *can* make a difference!
Not asking for credit myself, but it must be said that this is all thanks to Pistonheads, and proof that as a community if we all pull together, we *can* make a difference!
crankedup said:
So this must now mean that the informaion gathered from this type of device is inadmissible as evidence in court?
Hell no, unfortunately. Type approval is still there as far as I know. You will just have to go to court and bring all the evidence you can. For example, I brought a BBC report about the LTI2020 to court to find that it was 'hearsay'. Stewart was lucky enough to have a common sense magistrate who would read the report and have a CPS brief who didnt want to push the issue.
Another factor in the case was that Stewart got the guy to admit that there was a possibility that another car was zapped. That was a major coup and in effect would have won the case without anything else.
It is great news though, and the more cases there are like this that we can report through PH, then the more pressure gets put on, and thus more cases get overturned, and thus there is more information etc, until the LTI2020 use is stopped.
the best answer is to go to court - my uncle-in-law went about 4 years ago, defended himself and got off (he was speeding) on the fact that the guy had used the gun through the window as it was raining so as the glass distorts the laser the speed used was inadmissable!! also got the plod in question to admit in court that the gun used hadn't be checked /calibrated as per the guidelines.
magistrate threw it out and had a go at the police for not following their own procedures!!
magistrate threw it out and had a go at the police for not following their own procedures!!
Being the proud owner of an LTI 20/20 gun (the big brother of the Ultralyte) I can confirm that the guns themselves are accurate and it's usually human error that causes these anomolies that you hear about. "Speeding brick walls" can be caused by a movement of the gun at the time of firing or "gunshake" (for want of a better word!) I think it's going to be harder and harder for the police to justify using hand held laser guns as there's just too much room for drivers to arguing that the police officer moved a little when they fired the gun. However firing a gun from a tripod, inside a safety camera van doesn't tend to have the same "gunshake" problems so you'll see them continue. They're just too good at catching drivers and raising revenue (oops, of course I meant to say "encouraging us all to make sure we stick to speed limits at all times."
Don't give up you're jammers yet!!
Don't give up you're jammers yet!!
Am I missing something? I thought the Policeman had to form a prior opinion that a car was speeding before checking with the devise. He was obviously classed as competent to carry out the task, was he saying that he thought the car was doing the speed and the machine confirmed it? The bit about the overtaking car is a red herring if he had carried out the prior opinion safeguard correctly. I don't claim to be an expert but if I stand adjacent to the motorway I can differentiate between cars doing 70 and those 100+.
rayats said:
Am I missing something? I thought the Policeman had to form a prior opinion that a car was speeding before checking with the devise. He was obviously classed as competent to carry out the task, was he saying that he thought the car was doing the speed and the machine confirmed it? The bit about the overtaking car is a red herring if he had carried out the prior opinion safeguard correctly. I don't claim to be an expert but if I stand adjacent to the motorway I can differentiate between cars doing 70 and those 100+.
Thats the crux you see. You can differentiate if you do actually form a prior opinion. However in effect a lot of the time the only time 'prior opinion' is seen is when it as included as a formality in the laser speeding police statement template.
It must also be noted that if the laser checks are happening at 300-400 metres, to do a proper prior assessment with any kind of evidential integrity ie, approximate timings through a set fielf of distance, then this would have to be carried out at a distance of half a mile away, which makes the whole idea of the assessment holding up in court a bit shaky to start with.
Thus, although the idea should be that the prior opinion should be the primary evidence, the tables have turned. The problem comes when the user of the device is mistaken as to where the readin came from or if it were true. If the prior opinion is merely an afterthought, there is no back up plan.
allyoops said:
Being the proud owner of an LTI 20/20 gun (the big brother of the Ultralyte) I can confirm that the guns themselves are accurate and it's usually human error that causes these anomolies that you hear about. "Speeding brick walls" can be caused by a movement of the gun at the time of firing or "gunshake" (for want of a better word!) I think it's going to be harder and harder for the police to justify using hand held laser guns as there's just too much room for drivers to arguing that the police officer moved a little when they fired the gun. However firing a gun from a tripod, inside a safety camera van doesn't tend to have the same "gunshake" problems so you'll see them continue.
If the mounted camera doesn't move, I understand your point.
But what if the target vehicle turns to change lane at the moment the laser hits?
Is it possible the slip effect might come into play here as well...?
mybrainhurts said:
Being the proud owner of an LTI 20/20 gun (the big brother of the Ultralyte) I can confirm that the guns themselves are accurate and it's usually human error that causes these anomolies that you hear about. "Speeding brick walls" can be caused by a movement of the gun at the time of firing or "gunshake" (for want of a better word!) I think it's going to be harder and harder for the police to justify using hand held laser guns as there's just too much room for drivers to arguing that the police officer moved a little when they fired the gun. However firing a gun from a tripod, inside a safety camera van doesn't tend to have the same "gunshake" problems so you'll see them continue.
If the mounted camera doesn't move, I understand your point.
But what if the target vehicle turns to change lane at the moment the laser hits?
Is it possible the slip effect might come into play here as well...?
And what happens if a lorry drives past the Scamera Van just at the point of the speed gun being fired surely the wobble of the van / vibrations through the road would cause "gunshake" as well.
>> Edited by bunglist on Monday 20th March 14:26
>> Edited by bunglist on Monday 20th March 14:27
that would be dishonest 
rayats said:
Am I missing something? I thought the Policeman had to form a prior opinion that a car was speeding before checking with the devise. He was obviously classed as competent to carry out the task, was he saying that he thought the car was doing the speed and the machine confirmed it? The bit about the overtaking car is a red herring if he had carried out the prior opinion safeguard correctly. I don't claim to be an expert but if I stand adjacent to the motorway I can differentiate between cars doing 70 and those 100+.
Exactly, but it's really an excuse to be there with a speed gun in the first place.
>The issue arose following a case of a motorist who was at first accused of driving at >106mph on the M6 toll rod. Eventually, Stoke Magistrates Court acquitted the man, >Stewart Walker, on the grounds that the speed gun could have been measuring the car that >was overtaking him, a situation that a police officer under oath admitted was possible.
This guy was being overtaken when he was clocked at 106? A: Why was the copper aiming at him when the other guy was going faster? B: Not saying I do over 100 on the M ways but if I do I can count the number of times there has been anyone overtaking on the fingers of one hand even if I think back ten years.
This guy was being overtaken when he was clocked at 106? A: Why was the copper aiming at him when the other guy was going faster? B: Not saying I do over 100 on the M ways but if I do I can count the number of times there has been anyone overtaking on the fingers of one hand even if I think back ten years.
I'd echo the sentiment - ALWAYS go to Court. Make the prosecution work it's bollards off to prove the case. File a defence statement questioning the calibration of the device, the training of the officer to use the equipment, the sineage of the roads, etc... It creates a mountain of work for the prosecution and if everyone did the system would seriously struggle to cope.
NElmslie said:
>The issue arose following a case of a motorist who was at first accused of driving at >106mph on the M6 toll rod. Eventually, Stoke Magistrates Court acquitted the man, >Stewart Walker, on the grounds that the speed gun could have been measuring the car that >was overtaking him, a situation that a police officer under oath admitted was possible.
This guy was being overtaken when he was clocked at 106? A: Why was the copper aiming at him when the other guy was going faster? B: Not saying I do over 100 on the M ways but if I do I can count the number of times there has been anyone overtaking on the fingers of one hand even if I think back ten years.
He wasnt doing 106, the BMW that overtook him was. Somewhere between looking at the 'target' zapping the gun and radioing down to the chase team something got messed up.
justinp1 said:Maybe they tried to scam both of them for cash?
>The issue arose following a case of a motorist who was at first accused of driving at >106mph on the M6 toll rod. Eventually, Stoke Magistrates Court acquitted the man, >Stewart Walker, on the grounds that the speed gun could have been measuring the car that >was overtaking him, a situation that a police officer under oath admitted was possible.
This guy was being overtaken when he was clocked at 106? A: Why was the copper aiming at him when the other guy was going faster? B: Not saying I do over 100 on the M ways but if I do I can count the number of times there has been anyone overtaking on the fingers of one hand even if I think back ten years.
He wasnt doing 106, the BMW that overtook him was. Somewhere between looking at the 'target' zapping the gun and radioing down to the chase team something got messed up.
I have never used one of these devices, but it occurs to me that trying to "ping" a vehicle moving at 70 - 100 miles an hour with an infra red beam accurately must be pretty bloody difficult! If the gun only moves a fraction of a millimeter during firing, by the time the beam has travelled 300 meters to the target this could be an error of meters or more. I understand the instructions are to "ping" or "shoot" the number plate of the car the you are interested in but that in itself sounds difficult! It smacks to me of a device that gives a rough guide to a vehicles speed at best, and I certainly would not want to stake my life on it giving an accurate true reading of speed given the large body of evidence from various independent reports that prove they not accurate! 
The sooner these are banned and the police put back out on the roads properly the better IMO.
Cheers,
Steve
The sooner these are banned and the police put back out on the roads properly the better IMO.
Cheers,
Steve
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