http://www.eveningtelegraph.co.uk/output/2005/10/17/story7647560t0.shtm
Quote:
Assurances over speed camera
Tayside Police will continue to use a speed camera device despite growing evidence from both the UK and the USA that it can give incorrect readings, writes Steve Scott.
The LTI 20.20, a US-manufactured speed gun which can be hand-held, used from a tripod or from the window of a vehicle, is in widespread use by UK police forces but there have been growing instances of motorists caught by the device successfully challenging its readings in court.
A leading UK expert in laser technology, Dr Michael Clark, who himself overturned a speeding charge as a result of being clocked by the LTI .20.20, believes most laser speed guns used by police to trap speeders are prone to reflections which can give wrong readings.
In tests Dr Clark, by tracking an LTI 20.20’s beam across a stationary wall, managed to get a reading of 58 mph.
He has since appeared in court as an expert witness for a number of motorists who were clocked speeding with the device but were able to overturn the findings.
One motorist, a former police officer, had been clocked doing in excess of 70 mph despite the fact his car was on cruise control limiting the speed to below that level.
In the USA the LTI 20.20 — which is imported into this country by Tele-Traffic UK Ltd — was withdrawn from use in the state of New Jersey because of doubts over its veracity.
The LTI 20.20’s importers claim the “slippage’’ involved in the camera’s finding only amounts 2mph either way, and the device remains on the Home Office’s approved list.
A spokesman for Tayside Police said the LTI 20.20 was in active use across the region.
“It is one of a number of such devices that can be used by police forces in the UK — all of which are subject to rigorous field and laboratory testing to ensure their accuracy and reliability,’’ he said.
“Very specific guidance and training is given to officers using such devices.
He added, “A number of different speed detection devices are used in Scotland. These are used to great effect dealing with motorists who continue to disregard speed limits, placing themselves and other road users at risk.’’
If DNA testing had been proved to be so unreliable I don't think it would be alowed as evidence in court.