Drink Driving – Defences in Court

To be guilty of drinking and driving the prosecutor has to make a magistrates’ court sure that you were driving a vehicle and that the proportion of alcohol in your system was over the legal limit.

The limits for drinking and driving are currently 35 microgrammes of alcohol per 100ml of breath, 80 milligrams per 100ml of blood or 107 milligrams per 100ml of urine.

In most cases drivers will plead guilty and in reality the courts seem to expect that in most cases.

If you plead not guilty and take the case to trial then the prosecutor has to produce enough evidence to the court to convince the court (magistrates or district judge) to convict you.

If courts can only look at the evidence and apply the law then do legal loopholes exist.

They answer is no despite a lawyer being called “Mr Loophole”. 

There are only two ways of being found not guilty of a charge. Either the prosecutor does not provide enough evidence or you put up a convincing defence. There is no room in the system for a loophole. 

In all the years of dealing with drink driving cases I have never seen anybody acquitted due to a technical defect in the law.

That is not to say that I haven’t seen the CPS being forced to drop a case and the court returning a not guilty verdict. But none of those have been due to a loophole existing.

Drink driving defences fall into three distinct groups.

  • Cases where strict procedures have not been followed properly.
  • Cases where the police/prosecution evidence does not support the charge.
  • Cases where the defendant has raised a legitimate defence allowed by the law.

Strict procedures have not been properly followed

A lot of the procedures that the police have to follow can be found in the Manual of guidance drink and drug driving (MGDD) forms. The most common are MGDDA – police station procedures, MGDDB – blood/urine samples and MGDDC – hospital procedure.

Not offering half the sample. Section 15(5) Road Traffic Offenders Act 1988 says that the police must offer a suspect half of the blood or urine sample.If they don’t the prosecution will normally fail.

Medical authorisation not obtained. Section 9 Road Traffic Act 1988 tells the police what to do when they want to take blood from a suspect who is in hospital. It says that the police must obtain consent to take blood from the doctor in immediate charge of the patient’s care. If they don’t then the sample can’t be used in evidence. If there is no other evidence of alcohol levels there can’t be a conviction.

Proper consent not obtained for taking blood. Section 15(4) Road Traffic Offenders Act 1988 requires the police to obtain proper consent from their suspect to take a blood sample. If they don’t, the whole procedure could be excluded at trial.

Wrong doctor took blood. When a suspect is in hospital a blood sample has to be taken by a police doctor according to sections 7 and 7A Road Traffic Act 1988. No doctor who is involved in the care of the patient can take the sample. 

Blood/urine samples mixed up. This is pretty obvious but in reality it happens extremely rarely.

Samples have unique reference numbers which follow them from suspect to police station, to refrigerator, to courier, to laboratory to testing equipment. It is a straightforward process to check that it has been done correctly.

Not waiting 20 minutes before using breathalyser. Breathalyser machines can give inaccurate readings if the person providing the sample has eaten, drank or taken anything less than 20 minutes before providing the sample.

Police officers usually ask a set list of questions before starting the machine to make sure that this doesn’t happen.

Blood/urine not kept in the fridge. Samples have to be kept in proper conditions so that they do not degrade before they are tested in the laboratory.

Policeman was not wearing his hat. This is not a defence and will not work.

Statutory warning not given. A police officer has to give this warning before a suspect is breathalysed. (It must be a police officer, a police civilian employee will not do.)

“I require you to provide two samples of breath by means of an approved device. The specimen with the lower proportion of alcohol may be used as evidence and the other will be disregarded. I warn you that failure to provide either of these specimens will render you liable to prosecution.”

Witnesses not coming to court. If the evidence of a witness (including a police officer) is disputed that witness must come to trial.

They need to attend court in person to give their evidence and be cross examined. If the witness is not there then their evidence cannot be used. There are some rules and procedures that the prosecutor can use to try and correct this (they might apply to adjourn, ask the court to admit the evidence as hearsay or even carry on without the evidence).

If the lack of evidence from the witness means that the prosecution cannot prove the case you will be acquitted.

Non-disclosure. This is quite complicated and should be dealt with by a lawyer.

When a case goes to trial the CPS have a duty to disclose certain documents to the defendant or to their lawyers. The rules for doing this are in the Criminal Procedure and Investigations Act 1996 and in the Criminal Procedure Rules.

Charges laid out of time. Drink driving, drug driving and failing to provide a sample are all summary only offences which can only be dealt with in the magistrates’ court.

Nearly all summary charges must be laid within six months. If the police charge a motorist or issue a postal requisition more than six months after the incident it should be thrown out when it gets to court.

The police/prosecution evidence does not support the charge

Road/public place/private land. Drink driving and similar offences can only be committed on a road or other public place. If the location of the driving is not accessible to the general public the driver cannot be guilty.

It is possible to be guilty of drink driving on private land. But that land must be accessible to the public. A supermarket car park is private land but the public can go there.

No proof that the defendant was driving. You might think that it is rather strange that anyone is prosecuted when there is no proof that they were driving. It often happens and if the prosecutor cannot prove with evidence that someone was driving then there can be no conviction for drink driving.

Some people use this as an excuse not to provide the police with a sample of breath, blood or urine. This will not work. As long as the police suspect that you were driving they can ask for a sample. If you fail to provide that sample the penalty is as bad as for drink driving itself.

Breathalyser not working properly. Usually when a breathalyser is not working properly the police will either use another or require a blood or urine sample. 

If some evidence comes to light that the Lion Intoxilyser, Camic Datamaster or EC/IR Intoximeter was faulty or was not reading accurately that might be a defence.

Courts must assume that the machine is working. There is no need for the prosecutor to provide any specific evidence.

There was a House of Lords case in 1988 called Cracknell v Willis [1988] AC 150. That case says that if a motorist can prove that they should have been under the limit then the prosecutor has to call evidence at trial to prove the the machine was working. In reality this defence is almost never used.

The standard of evidence needed to displace the reading of the machine is difficult to imagine. The High Court gave an example and said that if the defendant court call evidence from a bishop who said that the driver had not been drinking, that might be acceptable.

Breath differences. The police take two samples of breath and use the lower one as evidence. If there is a difference of more than 15% between the two samples it could be unreliable.

The defendant has raised a legitimate defence allowed by the law

Post incident drinking. If a motorist drives vehicle, parks the car and then drinks alcohol the police may turn up and you are breathalysed and then you fail the breathalyser. If the alcohol consumed after driving could account for the breathalyser reading then you can be acquitted.

To run this defence the defendant has to prove their case on the balance of probabilities.

Two pieces of evidence are usually needed.

  1. Evidence of the amount of alcohol taken after driving. That might just be evidence from the driver him or herself. It could include supporting evidence from other people.
  2. Evidence from an expert who makes a calculation. That calculation computes the alcohol level caused by consuming that alcohol.

Special reasons. These only apply when a driver is guilty of drink driving (and other motoring offences).

If they can show that there are special reasons then the court might not to disqualify them from driving.

You will need to prove to Court that there are special reasons not to disqualify you from driving or not to give you penalty points.

If the argument works then you will still have a conviction for the offence but the court have a discretion not to give you the points or the ban.

After your guilty plea there will normally be an adjournment of the case.

The special reasons will be heard on another day. The court will hear evidence before they make their decision. You may have to give evidence in court yourself and you may need to call other witnesses. It all works a bit like a trial.

What is/is not a special reason

The most important thing to remember about a special reason is that it must relate to the commission of the offence. That means it must be to do with the events that happened on the day that you were actually seen driving.

A special reason can not be anything to do with you personal circumstances. If a driving ban is going to have a devastating effect on you that will not be a special reason.

Some examples of special reasons are:

  • Driving a very short distance
  • Escaping from an assault
  • Spiked drinks in a drink driving case
  • Young drivers relying on their parents to arrange insurance
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