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Drink Driving & Defences

The law and procedure in drink driving cases can be very complex

A person is guilty of the offence of drink driving if he drives or attempts to drive a motor vehicle on a road or other public place after consuming so much alcohol that the proportion of it in his breath, blood or urine exceeds the prescribed limit.

It’s as simple as that, but the consequences of a conviction are serious. They range from a period of disqualification of 12 months to imprisonment, as well as many others such as job loss.

The prescribed or legal limits are:

  • 80 milligrammes of alcohol per 100 millilitres of blood;
  • 35 microgrammes per 100 millilitres of breath;
  • 107 milligrammes per 100 millilitres of urine.

It is worth remembering that these limits apply in England and Wales and that in Scotland they are now reduced to 50 in blood and 22 in breath.

How much is it safe to drink?

People often ask how much it is safe to drink and there is no easy answer or fool proof way of drinking and staying under the limit. It depends on things like weight, gender, metabolism, the type of drink, stress levels, whether food has been consumed recently, and age. This can be explained with a simple example. A large male may take 2 hours to get rid of the alcohol in a pint of ordinary lager, but a female who is typically smaller may take 3 hours because the same amount of alcohol will be more concentrated in her body. Younger people may get rid of alcohol more slowly because their bodies are not as used to alcohol as older people. This is why estimating a safe amount to drink is difficult, and risky.

There is a separate offence of being in charge of a motor vehicle whilst over the limit known for short as being drunk in charge and this is dealt with separately.

The police have the power to require the provision of specimens of breath, blood or urine when investigating whether a drink drive offence has taken place. You may be asked to provide a specimen even though you know you were not the driver, but if the police require it as part of an investigation, it is an offence to refuse or to fail to provide a sample without a reasonable excuse. More information on this can be found on my failure to provide a specimen page.

The statutory power to require specimens is contained in Section 7 of the Road Traffic Act 1988, and because the process is one in which drivers and suspected drivers are effectively being required to provide evidence against themselves there are legal and procedural safeguards built in to protect people. This means that the police must carefully follow proper procedure. If they don’t, prosecutions can become unsustainable.

Having an understanding of the requirements and knowing exactly what to look for in the prosecution evidence is key to identifying defences or ‘special reasons’ and then deploying them effectively in court.

This is what I do. I have over 30 years’ experience of dealing with police officers’ evidence and know what to look for and how to challenge admissibility. Most people charged with drink driving assume the police get it right all the time and that measuring devices are infallible. This is not correct, and given the consequences of a conviction it is usually worth having the matter properly looked at. I can then accurately advise you on your options. You may have a complete defence, or you may be able to challenge the readings put forward by the prosecution and sentenced on a lower level of alcohol. You may be able to put before the court a good explanation why the offence took place and mitigate the sentence.

Unless you take advice you may never know

Drivers charged with drink driving invariably leave the police station with a charge sheet and bail form, a breath testing machine printout, and nothing more. Within a few days the police will pass all their basic witness statements to the Crown Prosecution Service who will make them available at court. Obtaining and reviewing these papers is essential. So is obtaining and reviewing the CCTV recording of the time in the police custody suite when there should be an audio and visual recording of everything. I have encountered occasions when the recording has become corrupted and unusable, or of such poor visual or sound quality that it cannot be relied on. Sometimes the CCTV supports a driver’s version of events and conflicts with police written statements, or is otherwise just very helpful in establishing whether the driver has been charged with the correct offence.

None of this will be known unless proper enquiries are conducted.

A trawl of the internet may leave you thinking that there is a defence or way out or loophole to be found in most cases. This is not so and I am careful not to raise expectations unrealistically. This can so easily turn into an expensive mistake.  However, I am thorough and honest with my clients and where a proper defence is identified it is pursued tenaciously.


Defences to drink drive charges fall into two broad types. I will call them ‘factual’ and ‘technical’

An example of the first type might be that you were not driving. This might be appropriate for example if you were incorrectly identified, or if the activity you were undertaking was not ‘driving’. The word has a legal meaning. The court in such a case would look at the extent to which you were in control of the movement and direction the vehicle.  Some prosecutions depend on visual identification evidence of the driver from bystanders and this can be properly challenged when it’s incorrect. Unless the Court is satisfied that you were the driver or were driving, it cannot convict you.

Another example might be that the vehicle was not being driven on a road or other public place. This is an essential ingredient and it’s for the prosecution to prove it. Private land will plainly not be a ‘public’ place, but what about a car park, or private road, or piece of land that is open to the public for only some of the time and otherwise private? This might apply to a pub car park that is open to the public during opening hours but otherwise ‘private’. You can begin to see it’s not always straightforward.

Sometimes people drive in an emergency or under duress (known as duress of necessity or duress of circumstances), and what happens then? These are both capable of being defences and even though they might not succeed the court can use the same evidence to support a finding of ‘‘special reasons’.

The second type of defence can properly be described as ‘technical’ in the sense that it is a forensic analysis of the procedure leading to the production of the sample of breath, blood or urine that forms the basis of the prosecution.

The burden is on the prosecution to prove the sample is both admissible and reliable, and if it can’t the prosecution will fail.

The following are examples of what might constitute such defences, but it’s not exhaustive and individual circumstances will vary:

  1. The police failed to give a warning at the time the samples were required that a failure to do so would be an offence. This is a mandatory statutory requirement and its absence is fatal to a prosecution;
  2. The police fail to give the warning in an intelligible and understandable way. This is particularly important when having a warning translated. This must be done accurately so the driver completely understands what is being said;
  3. The device taking the samples of breath was defective. You might have only consumed a small amount of alcohol, or consumed your last alcoholic drink a considerable time beforehand (see morning after) and yet the device produces a reading out of all proportion. Alternatively, you blow firmly and at length and the device records a fail, leading to a charge of failure to provide. These are possible indicators the device is not functioning correctly, and maintenance logs need to be obtained and analysed. It may also highlight the need for a spirometry test to check your lung capacity or capability;
  4. The consumption of alcohol after driving. Not all drivers are stopped by police whilst at the wheel and if you drank after you stopped driving any sample provided will include that additional alcohol. You may be able to show that were it not for the additional post driving alcohol you would not have been over the legal limit and if you can you have a valid defence;
  5. Rules apply to the taking of blood, who can take it and the division of the sample. Other rules apply to the times for taking urine and the division of samples. If the environment is such that the driver is unable to provide a urine sample and simply can’t go because of the way the police behave, the breath sample may not be admissible. An inability to “go” is surprisingly common in males and females;
  6. The same rules apply if for some reason the Police decide to take a specimen of blood or urine at the outset rather than breath. This might apply for example if the breath device is not working, or if you are in hospital;
  7. The police must tell you that you have a right to take part of the sample of blood or urine with you so you can get it analysed yourself. If that’s not done the result the police get from their own specimen may be excluded;
  8. The prosecution may have to demonstrate how the samples of blood or urine were moved from person to person so that proper continuity is established;
  9. The taking of a breath sample too soon after the last drink so that alcohol remains in the mouth causing a higher reading, or the stomach brings alcohol up with the same result, or alcohol is trapped in the mouth in dentures or crowns.

Special Reasons

If you are convicted of drink driving or attempting to drink and drive, the court must disqualify you for a minimum of 12 months if it’s your first offence and longer if it’s not. The only way to avoid a disqualification or to secure a much shorter one is to establish a ‘special reason’.

A ‘Special Reason’ is an expression which has a particular legal meaning. The majority of motorists can easily put forward reasons why an offence was committed, but the law distinguishes between reasons which are routine and ordinary (for example: it was not deliberate, I misjudged the amount I was drinking, I thought a night’s sleep would sort me out) and those which are so closely connected with the commission of the offence that they attract the title ‘special’ and open the way to not being disqualified.

Special reasons are not defined by statute but the basic definition used by the Courts is taken from a case decided in 1946 and remains good law. To be a special reason it must:

  1. be a mitigating or extenuating circumstance;
  2. not amount in law to a defence to the charge;
  3. be directly connected with the commission of the offence; and
  4. be one which the court ought properly to take into consideration when imposing sentence.

The following are examples, but again it’s not an exhaustive list:

  1. The fact that a motorist drove for a short distance and in circumstances where he was unlikely to be brought into contact with other road users. I have successfully argued this in drink-driving cases where the court decided not to disqualify it all;
  2. The fact that a motorist’s drinks were laced and he did not know he was consuming alcohol. I have successfully argued such cases;
  3. The fact that a motorist was given drinks stronger than he asked for and didn’t know;
  4. That the driver has an alcohol elimination rate that is unusually slow. This might for example apply to someone caught drink driving the morning after. There is a way of testing elimination rates and a slow one can support a special reasons argument;
  5. That the driver perceived a genuine emergency and drove only so far as was necessary to deal with it, or was otherwise compelled by duress.

It’s important to remember that the evidential burden lies on the driver to prove a special reason but it’s to the lower civil standard, on a balance of probabilities.

It’s also important to understand that most ‘technical’ defences and special reasons arguments will need expert witness evidence to support them.

Attempting to drive whilst over the legal limit

The offence is committed when someone attempts to drive after consuming alcohol over the legal limit, and it is measured in the same way by taking a specimen of breath, blood or urine.

Someone ‘attempts’ to drive when they do something more than merely preparatory to the commission of the full offence. The ‘full offence’ is driving and to embark on the ‘crime proper’ something has to be done as part of the process of putting the vehicle in motion.

Turning on the engine is an obvious example of how the offence of ‘attempting to drive’ might be proved, whereas just opening the car door would probably not be enough. That step would most likely be seen as merely preparatory and not part of the process of putting the car in motion.

All such cases turn on their own facts and it is a question of degree.

Mitigating your sentence

The absence of a defence or  ‘special reason’ is not the end of the matter because sincerely presented explanations and mitigation will still influence the court’s sentence. The importance of this is often underestimated and real benefit can come from well presented mitigation aimed at persuading the court to sentence you more leniently. Good quality written testimonials from family and close friends can be particularly helpful to enable a court see the offence was out of character and that there is genuine regret.

Just get in touch with me and I will explain how I can help. 

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