If you are arrested on suspicion of driving under the influence (DUI/DWI) in California or elsewhere, you will be asked to take a chemical blood alcohol content (BAC) test.
This is a test conducted at the police station (or medical facility) to which you are taken after an arrest on suspicion of DUI/DWI.
The purpose of the test is to gather evidence of intoxication over and above the evidence which gave probable cause for the arrest.
Chemical BAC tests are performed on a sample of breath, blood or urine – most often a breath sample. Blood or urine will be more likely if there is a suspicion of driving under the influence of drugs (DUID).
The sample will be chemically analyzed to determine the level of alcohol (and/or drugs) in your system.
BAC Test Results and Consequences
In all states, a blood alcohol level of 0.08 or higher is the “per se” level of intoxication.
This means that a blood alcohol level of 0.08 is sufficient proof “in and of itself” of intoxication with no other evidence of required. However, this “presumption” of intoxication is refutable – one of the many things that a good DUI lawyer can do for you.
If your blood alcohol content level is 0.08 or higher, you will be charged with “DUI per se”.
If your blood alcohol level is less than 0.08 you may still be charged and possibly convicted of DUI/DWI.
This is because most states have additional charges that can be made, based on other evidence of impairment (for example, what officers have observed). Where possible you will be charged with both – “DUI per se” and an impaired driving charge based on what officers have observed. This gives prosecutors the best chance of a conviction.
In most states, BAC levels significantly higher than 0.08 will also trigger enhanced DUI charges.
Do Not Confuse BAC Tests and Roadside Breath Tests
Although the most common form of a chemical BAC test is a breath test, this is not to be confused with a breath test given at the roadside. Breath tests at the roadside are “preliminary alcohol screening (PAS) tests“, conducted to establish probable cause for an arrest. In almost all states you can refuse PAS tests.
If you have taken a breath test at the roadside, you will still be asked to give a sample for a chemical BAC test. Legally, they are two quite different tests.
Refusing a Chemical BAC Test
In all states, you implied your consent to a chemical BAC test at the time you applied for a driver’s license. This “implied consent” is based on the principle that driving is a privilege not a right. As such, drivers are deemed to have agreed (without actually saying so) to provide a sample for a chemical BAC test if arrested on suspicion of DUI.
Technically, you may still refuse the BAC test – but this is not advised.
- If you refuse the test you will almost certainly be arrested anyway, charged with driving under the influence on the basis of what officers observed.
- Some states have options for compelling a BAC test.
- By refusing the test you are breaking the conditions under which the license was issued. The consequences of refusal typically include immediate suspension of your license with additional penalties imposed by the court.
- License suspension is a department of motor vehicles (DMV) action and may be upheld even if you are subsequently found not guilty of drunk driving. (Penalties applied by the DMV and the court are separate.)
- If you take the test and your BAC is 0.08 or higher, you will not necessarily be convicted. The presumption of intoxication is refutable, a DUI lawyer may identify errors in procedure which make the test inadmissible, and so on.
BAC Tests Must be Conducted Lawfully
Chemical blood alcohol content tests must be requested and performed lawfully, following procedures laid out in state law.
For example, in most states – exceptions exist – a BAC test can only be requested and conducted after a lawful arrest in which you have been read your Miranda rights and been informed of your rights regarding the BAC test as well as the consequences of refusal.
Additional conditions vary from state to state but may include the right to choose the type of sample given (blood, breath or urine), the right to first consult with a lawyer, the right to obtain a second independent test, and so forth.
A good DWI/DUI lawyer will of course know which questions to ask you, to determine if your BAC test was lawful.
The above information applies to private drivers aged over 21 and not on parole. DUI laws differ for other categories of drivers.
Copyright © 2010 Caroline Mackenzie