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BAC Tests and Your Privacy

Posted by John Campanella | Mar 22, 2018 | 0 Comments

Because driving under the influence (DUI) is a crime in California, DUI-defense attorneys are technically criminal defense attorneys who focus their practice on a small niche. However, just because DUI-defense attorneys only defend one particular crime does not mean they can't use the legal defenses that other criminal defense attorneys use for their clients.

One of these defenses is that the protections of the Fourth Amendment become stronger, the deeper the police intrude into your privacy. In the context of DUI-defense, this makes a big difference when police ask you to take a breath test, a blood test, or a urine test.

Privacy Expectations and Your Fourth Amendment Rights

Typically, the Fourth Amendment prohibits police searches if they don't have a warrant to do one. However, there are a handful of exceptions to this rule.

These exceptions are largely driven by your expectation of privacy. If you have a strong expectation of privacy, then any search by the police is more likely to require a warrant. On the other hand, if you don't expect privacy in something or in a course of conduct, or if expecting privacy would be socially unreasonable, then the police are more likely to be able to gather evidence against you without having to get a warrant, first.

For example, if police can see evidence that you have committed a crime from where they stand on public property, then they will not need a warrant because you have a very low expectation of privacy.

Privacy in DUI-Defense: Breath, Urine, and Blood

One way that privacy expectations can be used to defend against a DUI charge is through the different kinds of chemical tests that police use to determine your blood alcohol content (BAC). There are three different kinds of chemical tests that police can use:

  1. Breath tests,
  2. Urine tests, and
  3. Blood tests.

Some of these tests are more accurate than others. Breath tests, for example, are notoriously prone to picking up environmental factors that inflate a BAC reading and get innocent drivers into trouble.

However, some of these tests are also far more invasive than others. Blood tests involve inserting a needle into a suspect's arm to draw blood straight out of a vein, while breath tests only trap the air that a suspect would have exhaled, anyway.

Additionally, the amount of information that can be collected by each of these tests impacts how badly they invade your privacy, as well. Breath tests only read the amount of alcohol on your breath, while the blood taken during a blood test could, at least in theory, be used to sequence your very DNA.

These levels of privacy that you can expect in your blood, urine, and breath are a big obstacle for a police DUI investigation because they can force police to get a warrant before searching for evidence of drunk driving. This often prevents police from gathering more than a breath test, which is much easier to challenge in court than the results of a blood or urine test.

Sacramento DUI-Defense Attorney John Campanella

If you have been charged with a DUI in or near Sacramento, call DUI-defense attorney John Campanella at (877) DUI-JOHN or contact him online for the legal help you need.

About the Author

John Campanella

I have been representing people accused of drunk driving since I began practicing in 1995. I went to my first Sacramento DUI conference that year and listened to great DUI attorneys like Ed Kuwatch AKA, “Fast Eddie” and Lawrence Taylor who motivated me to study and practice in this area of law.


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