In about 1990 the Home Office withdrew its approval for hand-held speed guns - recalled all guns from Police Forces and destroyed them. There may now be guns with approval as my Home Office Department was bought by NTL in 1994.
If anyone is caught by a Police Speedgun it may be worth checking if the gun has Home Office Approval and a valid Calibration Certificate. If you create doubt especially potential embarrassment for the Police you may hear nothing further. The Policeman should show you the reading. In Scotland it would be Scottish Office Approval and in Scotland there must be two policemen operating the gun.
If the Police stop you at a camera and warn that you are being reported for speeding they can process you anytime, but if you only receive a letter it must be within 14 days unless there are special reasons ie you have moved house etc. The advice was valid in the '90s and probably still is.
As part of the training delivered we were told to show the driver the speed, distance, last calibration date and next due calibration date (sticker issued by the manufacturer on the side of the device) and state "this is the [insert name of device], a Home Office approved speed detection device, which I am trained and authorised to use" at the roadside.
Different Forces use different equipment but all do need to be Home Office approved
Only ones likely to be using them are Roads Policing Teams or Road Safety Partnerships, and we're not using a converted hairdryer off eBay!
Your terminology is a little off, we don't warn we inform people they will be reported for the offence when it comes to speeding, a warning is a disposal option (think informal warning here). If a warning is issued then that's the matter done and dusted, such as a S.59 Warning.
Ref the 14 days - doesn't apply if you are stopped at the roadside by us and informed you will be reported for the offence, you are referring to static GATSO type cameras or vans. It's known as an NIP (Notice of Intended Prosecution), gives you 14 days as the owner of the vehicle to identify the driver and accept the offer of a fixed penalty or training course.
Also your advice to see the calibration cert - careful with that advice, you won't cause embarrassment but to see the calibration cert you will need to refuse the offer of a conditional fixed penalty notice and opt for court hearing, we're not required or obliged to produce any evidence at the time of reporting for the offence, we show the calibration sticker as good practice for this type of offence.
i had some refuse last year, went to Magistrates Court, found guilty, appealed to Crown Court, still found guilty. 8 points and £1200 later (costs and victim surcharge included) he gave up, 37 in a 30, outside a school.
