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Jo C.
Jo C., Barrister
Category: Law
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Experience:  Over 5 years in practice
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My son has just failed drink driving blood test, 90mg in 100

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My son has just failed drink driving blood test, 90mg in 100 blood. He had an accident, no one else involved no damage to any other property. his car written off as he hit a tree.
He failed a breth test taken in hospital, then had a blood test. The police doctor attended the hospital, the blood was taken from a hospital drip line inserted into a vein, not directly from a vein, does this has any impact on the legal procedure. Also we have a second sample of blood is it worth getting this tested and how do we go about this? My son is 19 years old first offence.

Thank you for your question. My name is XXXXX XXXXX I will try to help with this.

Did he provide a breath test at scene and what was the reading please?
Customer: replied 4 years ago.

He was injured and taken to hospital, breath test was taken in hospital, they did not give reading the police officer just said it was a fail.



If this is 90 on blood then thats a fairly low reading. It might be worth a second. Analysis to see if it falls under. The limit is 81 ml but that only equates to 35 mg in breath and they would not normally charge unless a person blew over 40 mg in breath. Blood tests are thought to be more accurate though so its a risk but a second analysis wouldn't be a bad idea.

The fact of the drip wouldn't make any difference unless there is any suggestion of tampering which is obviously unlikely.

The aggravating feature is the accident.

However, if this is 90 ml then he is only facing a fine and a ban of between 12-16 months. If he does the drink driving course that he will probably be offered then that will shave off one quarter but there is a cost.

Also if he pleads there will be costs of £85. If he contests the matter and is convicted then the costs will be about £350.

There will be a victim surcharge that reflects his means.

He should not drive to court. He will be banned and unable to drive home and you will not believe the problems he will save himself but getting on a bus instead

Can I clarify anything for you?

Customer: replied 4 years ago.

Thank you for your answer, can you clarify

1. if i get the second sample analyised and it falls below the 80 will the police use the failed breath test to charge him, this was taken some time earlier?

2. Do the police have to disclose now what the failed breath test reading was?

3. I have a second blood sample given to us at the time the blood was taken in a sealed bag, how do I get this tested so that it is permissable evidence if it falls below the 80 ml?

4. What happen if this second test is a higher reading.



1 The sample you have should have been taken at the same time that they took a specimen? Thats what normally happens.

2 No because it was failed so there won't be a reading.

3 Try here

4 There's no way it could if it was taken from the same specimen but you are not under an obligation to disclose that if it were to happen.
Customer: replied 4 years ago.

Thanks, XXXXX XXXXX clarify

If we got the blood sample tested and it was below 80 (yes it was taken at the same time) we could use this even though the police gave him as breath test as well earlier which he failed?

can they just use the breath test to charge him?

Yes, that would be a challenge.

They can't rely on a failed breath test as, by definition, it failed.
Customer: replied 4 years ago.

one further point, when i talk about a failed breath test I mean he was over the limit on the breath test and they then asked him to provide a blood sample.


Is that your understanding of what I was asking?

No, I thought you meant the machine failed.

I think he probably blew between 40-50. Thats why they sent him for a blood test which is unfortunately slightly over.

Normally they will not charge a person unless they are over 40 even though the limit is 35 unless a blood test is over 81ml.
Customer: replied 4 years ago.

So do they have to disclose now the breath test reading?

If it was over 40 they could charge him based on breath test alone, even if the second blood sample was below 80?

Not if they are not relying on it but if they are asked then they will disclose it.

If it was over 40 they could rely on the breath specimen but usually they will only do that if the blood reading it over 81ml.
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