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Can you win a drink driving case?

1. The Authorisation permitting the setting up of the police checkpoint was defective.

2. Police officer had unlawfully detained motorist at side of road before later arresting them.

3. Officer gave evidence at trial that they arrested motorist in a place not referred to on the summons.

4. Motorist provided a urine sample, but the summons referred to a blood sample.

5. Officer saw motorist smoking in traffic and used the drug testing equipment incorrectly.

6. State prosecuted for drug driving but charged motorist with an offence that carried a 4- year disqualification instead of 1 year.

7. Witness did not turn up for the trial.

8. Officer gave evidence of time blood sample given but his notebook gave a different time.

9. Essential Prosecution document not in Court.

10. State could not prove time of driving.

THESE EXAMPLES ARE cases of mine where the prosecution for drink or drug driving was dismissed. What should -hopefully- be apparent is that each of these cases were dismissed despite the motorist having exceeded the alcohol limit. In at least one of these cases the client was five times over the limit but was still acquitted.

Just because you’re over the limit,
even well over the limit,
doesn’t mean you will definitely
be disqualified from driving.

First, some pointers.

Just because you’re over the limit -even well over the limit- doesn’t mean you will definitely be disqualified from driving.

Read that again.

Your blood/alcohol (or breath or urine) level isn’t the end of the case; it’s just the beginning.

The last official records on drink driving acquittals in Ireland indicated that -on average- 66% of all drivers prosecuted for drink driving were convicted.

That meant that about 34% of drivers were acquitted.

Every one of these 34% were over the limit.

If your blood/alcohol level was the only thing that mattered in these cases everybody would be convicted.

That number above would be 100%, not 66%.

That fact should indicate that the level of alcohol in your blood is not definitive.




Up to the late 1920’s in Britain there was no such thing as a drink driving limit. It didn’t exist. But with more and more cars on the road came more and more examples of people drinking and driving and more and more deaths.

Something had to be done.

Governments in the West had a problem. How do you protect the public without infringing individual freedoms?

This was a major issue in the United States where there is a long tradition of opposing State encroachment in the lives of citizens. There were serious constitutional concerns about the proposals that the individual States of the Union proposed to make.

Experts were worried about the legality of demanding that motorists under arrest could be forced to allow a sample of their blood to be removed from their body.

It was one thing to collect a sample of breath, a substance that would only be harvested after it was expelled by the body; it was another to remove a life-giving substance like blood from a person.

With breath you would be collecting something that had already been expelled. With blood you were taking something that was vital to the very existence of a person.

What’s more, you would be demanding that the citizen gave that sample because nobody would voluntarily give something that could later end up convicting them. In effect, you would be asking the citizen to help the State prosecute them.

In democracies which cherished ancient principles like the right to silence and the privilege against self-incrimination this posed a major headache.

In the end the various legislatures across the United States were persuaded that the public's right to safety on the highways of the country far outweighed the individual's right to exclusive domain over their own bodily fluids.


But demanding blood, urine or breath samples is not to be taken lightly.

Courts take this matter very seriously.

I heard one Judge recently express the view that if the State “were going to stick a needle in someone’s arm and take blood from them”, then the State needed to follow the law correctly.

There are various procedural and legal steps that must be successfully navigated before a sample is deemed to have been lawfully taken. If these steps are not taken or if the law is not followed, then the evidence obtained (i.e., breath, blood or urine) may be deemed to have been unlawfully obtained.

If this happens the Court may dismiss the case.

There are certain steps that are regarded as essential issues in a drink driving prosecution. In other words, there are things which must be proven by the State in evidence. If they are not, the case will be dismissed.

Again, the level of alcohol in your breath, blood or urine, while relevant, is not definitive. If the legalities are not proven the case is dismissed even if you're over the limit.


Firstly, the charge.

In broad terms the State must prove that you drove a vehicle in a public place while there was excess alcohol in your system and that because of that you could not properly control a vehicle.

The State must also prove that the sample was taken within the correct time period. The police have three hours to get the breath, blood or urine sample from you.

That means that the State must be able to prove that the sample was taken within 3 hours of driving. If the sample is taken 3 hours and I minute after you drove, the case will be dismissed.

This obviously means that they must know what time you drove. If they cannot prove what time you drove, they will have great difficulty in proving a drink driving case against you.

Great difficulty, but it is not impossible.

HOW DO THE STATE PROVE the time that you drove?

Well, obviously if the police are driving behind you and pull you over, they’ll have no difficulty proving this.

But if they don’t witness you driving, how do they prove it?

Remember, this is a criminal trial. You shouldn’t speculate about these things. The standard of proof is quite high: beyond a reasonable doubt. So, knowing what time exactly that you drove is an essential element of the case.

For example, say you have had some drink and decide to drive. Say you lose control and crash into a ditch. It’s a single vehicle accident. Nobody else is involved. The police arrive after receiving a call. How do the police know what time the accident happened, what time you drove at?

Unless a witness tells them that they saw the accident take place they'll have major difficulty in proving this essential element of the case.

That's why the police often ask will ask the driver what time the accident happened.

Even then though, if the police do ask you at the scene of the accident what time you drove, they should caution you before you answer that question. The reason they should do this is precisely because they ought to know that the answer you give will very likely help them prove their case against you.

As the statement that you make is incriminating and could end up helping to prosecute you, the police should caution you before you answer this question.


Because we live in a democracy and the law has long understood that people are not legal experts and may blurt out something that later incriminates them.

That is why the courts have required the police to caution people where the police think that the person may be a suspect.

But exceptions to rules do exist.

In road traffic cases, one exception is where the police are investigating an incident involving a car e.g. an accident

On the way to the scene, they encounter you walking. If the police officer stops next to you and asks you some questions (e.g. directions on how to get to the accident) and you make an admission of driving, that admission may be admissible even if the officer did not caution you.

This is because in this second scenario the officer does not necessarily know that you are a suspect in any potential offence. In his mind you may just be somebody who is out walking and may have witnessed something. In that moment he's unlikely to know that you are a potential suspect in a road traffic offence.

However, if he arrives at the scene of a single vehicle accident and encounters you next to your car which has crashed, he should caution you before he asks any questions.

He should do this because there is only one car involved and only one person at the scene: you.


But it would be wrong to suggest that in every drink or drug driving case the State must prove the time of driving.

They do not.

There are 4 different charges that the State can choose when prosecuting for drink driving.

One refers to excess alcohol in your blood, another to excess alcohol in your breath and another to urine. All three of these charges require the police to be able to prove what time you drove at.

I heard one Judge recently express the view
that if the State “were going to stick a needle
in someone’s arm and take blood from them”,
then they needed to follow the law correctly.

But the fourth charge does not.

The fourth charge is technic­ally called section 4(1) of the Road Traffic Act 2010. It’s been around for a long time in one form or another. Its predecessor was originally introduced into law back in 1961.

This charge is a "subjective" prosecution.

Here the State are not relying on scientific evidence to help them prosecute you (i.e. the analysis of your breath, blood or urine) but rather an assertion by the officer.

This is a subjective test i.e. "opinion" evidence. Here the officer is trying to convince the court that you were incapable of driving when they met you at the scene due to alcohol.

This is arguably harder to prove than the other charges which at least are backed up by scientific analysis of the amount of alcohol in your system.

Why would the State choose this harder charge and not one that scientifically verifies the level of alcohol in your breath, blood or urine?

The usual answer is because neither the police nor anyone else witnessed you driving and so cannot establish what time that you drove.

Another reason may be that the sample of breath, blood or urine was taken more than 3 hours after you drove.

The State always has more options.


The law is set up to give them every chance to successfully prosecute you.

Even if they cannot prove what time you drove, even if they don’t know if you actually drove, they can still ask the trial Judge to amend the charge before the court from Drink Driving to Drunk in Charge.

All the same, these are just some of the many ways that drink and drug driving cases can fail.

These cases are not easy.

The police are very well trained in this area and the High Court has shown a repeated reluctance to “second guess” every decision an officer takes in the middle of a roadside operation.

But the area is more complex than might appear at first glance.

Courts value fairness and the law must be equitable. That is what separates democracies from other forms of government. The courts are there to restrain the State when it oversteps the boundaries of fairness.

What should be clear is that regardless of the quantity of alcohol in your system, if the procedures are not followed or if the law is not strictly observed in certain key areas, the drink driving charges against you may be dismissed.

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