Clients always ask me “which one SHOULD I have taken – the blood test or breath test?”. The answer depends on the unique circumstances of the case. Here are some positives and negatives to consider when deciding to take a blood or breath test. If you would like more information or have been charged with a DUI, call Ozols Law Firm today for a free consultation.

The Blood Test

When the phlebotomist takes blood then they have to take two vials of blood. Title 17 California Code of Regulations states that they must take two vials so that one vial can be used for the prosecution and one can be used for the defense. They have to preserve both samples so that if the defense ever wants to retest the blood they can request it and bring it to their own lab. This is called a blood split, which can be used to show that there was

  • contamination in the sample, or
  • that it was not mixed properly, or
  • that the BAC is actually different than what was reported.

The blood test is also good for people with diabetes. Now Diabetes, which I will write about later, is something that can cause problems in the blood test and the breath test as well. If your levels are not correct in your body this can give an improper reading in the blood.

If you have been taking any other substances that day and you think the officer may suspect it, it is probably best to opt for the breath test.

One thing to take into consideration is one has a right to REFUSE the Preliminary Alcohol Screening test, which is the breath test that is done at the scene. If you are planning to take a blood test it is a good idea to refuse this Preliminary Alcohol Screening test. A lot of an attorney’s defense will come by questioning the chemical test used. If it seems like there could be an issue with the blood test, but you took a voluntary breath test as well, this will go against your attorney’s defense and make your case a little harder to fight.

The Breath Test

The breath test is a chemical test that is done later at the station. First, these tests need to be calibrated property. They have to have less than 150 people blowing into the device when you use the device.

Breath tests can be inaccurate because they are determining your BLOOD alcohol level from your breath. There are always issues of mouth alcohol, like whether you just drank alcohol, you’ve vomited, or if you were smoking or chewing gum and what you have eaten that day. These tests can be shown to be invalid just as well but there are issues on each test.

Title 17 also says that the breath test must have been within 0.02 of each other to be a valid test. Rarely, but it does happen, these tests produce different results, this can go to the weight of the prosecutors argument at trial and can show that the test is likely inaccurate.

If you take a breath test, again, it is not the best idea to take the preliminary alcohol screening test. It is easy for an attorney to argue that one machine was faulty but creates a problem to argue it on two separate machines with two separate tests.

The one thing to remember is if you take a breath test, it can never be retested.

If you have been charged with a DUI, call San Diego DUI attorney Alex Ozols for a free consultation.