When it comes to measuring blood alcohol content (BAC), law enforcement officials tend to rely on breathalyzer samples in conjunction with field sobriety tests. However, there may be certain circumstances that require authorities to arrange for blood samples to be taken.

DUI blood testing is one of the most accurate ways to measure BAC. It's important to understand the ramifications that this could have on your DUI case and what your rights are when it comes to blood testing.

Are You Required to Take a Blood Test?

If you're stopped at a sobriety checkpoint or pulled over on suspicion of intoxication, the responding officer can't force you to take a blood test right then and there. According to Missouri v. McNeely (2013), there must be probable cause for a law enforcement officer to obtain your blood sample, in most cases. Probable cause usually comes in the form of a DUI arrest after failing field sobriety testing and/or breathalyzer testing. Some states have implied consent laws that allow officers to demand blood testing without a warrant.

So what happens if you refuse to undergo DUI blood testing? For starters, you could end up losing your license for some time, depending on the seriousness of the offense. In California, refusing a blood test means you're subject to "refusal enhancement penalties" ranging from driver license suspension for 1 year and 48 hours in jail to 3 years without your license and up to 10 days in jail.

What's the Difference Between Serum Blood and Whole Blood?

Another factor that can determine the outcome of your DUI case is whether your blood sample was tested as a whole blood or serum blood sample. There are several notable differences between these two types of blood samples:

• Whole blood samples contain all of the platelets, plasma and other contents normally found in a typical blood sample. Whole blood is often referred to as "legal blood" due to its common acceptance in DUI court cases. These samples are typically drawn at the scene or during the booking procedure by a trained paramedic or nurse.
• Serum blood samples, on the other hand, contain only the liquid fraction of whole blood. Serum blood usually contains higher concentrations of blood alcohol than whole blood. As a result, the sample results have to be converted to a whole blood equivalent before being used as evidence in a DUI case.

How Can Evidence from a Blood Test Be Suppressed?

Blood samples don't make a slam-dunk DUI case. Instead, the blood samples must be weighed against other evidence to ensure a fair trial for the driver. In some cases, it may be possible for your attorney to throw out most or all of the case against you if the following occurs:

• Your blood sample was taken without a warrant, barring implied consent or extenuating circumstances that require foregoing an arrest warrant.
• The sample was drawn by someone other than a trained paramedic or nurse. Only medical personnel should attempt to draw a blood sample.
• There's no sworn law enforcement official available to witness and oversee the sample being taken.
• You're taking medication that creates a false positive when it comes to taking samples.
• The sample is damaged due to improper storage or chain of custody issues, raising questions of inaccuracy and sabotage.

All of the above factors can easily dictate the outcome of your DUI case. As a result, it's always important to have excellent representation on your side. An attorney specializing in DUI and DWI cases may be able to place the legitimacy of any blood test under suspicion and scrutiny. It's a good idea to consult with an attorney from a firm like Chichester Law Office at the start of the DUI case.