DUI Chemical Tests

When a person is arrested for a DUI, they are required to submit to a chemical test that measures their blood alcohol level. For alcohol DUIs, the police are required to give the choice of breath or blood tests. For drug related DUIs, the police may offer a urine test as well. If you don’t take a chemical test, your case will be treated as a DUI refusal and you face a one-year license suspension.

DUI PAS test

The preliminary alcohol screening device (aka PAS device) is a handheld breathalyzer that the police administer before being arrested. This test is optional and the police are required to tell you that you have the right to refuse the test. This test should always be refused. There’s no reason to give the police extra evidence against you, unless you believe that your blood alcohol level is less than .05%. If your blood alcohol level is .04% or less, then there is a legal presumption that you are not under the influence of alcohol. The police have discretion to arrest you if your blood alcohol level is .05% or more. Although the PAS device is a handheld breathalyzer, it is NOT the same thing as a chemical test. If you are arrested, you have to submit to a breath test or blood test, even if you’ve already blown into the PAS device.

DUI Breath Test

All breathalyzers operate in the same way. The machines measure the amount of alcohol in a person’s breath and then use that number to calculate the amount of alcohol in a person’s blood. In order to understand how a breathalyzer works, you have to understand how alcohol is absorbed in the human body. When person drinks, alcohol is absorbed into the blood stream and then travels to other parts of the bodies, including air in the lungs. Breathalyzers measure the amount of alcohol in the air expelled from the lungs and then translate that number into an ESTIMATE of the amount of alcohol in the blood. This process is not an exact science and experts generally agree that breathalyzers have an inherent range of inaccuracy, ranging from .015% to 0.2%. That means if you’re blowing a .08%, your blood alcohol level could really be as low as .06%.

Other factors can also affect the accuracy of breathalyzers, including whether the device was properly calibrated, the presence of mouth alcohol, certain medical conditions and the temperature of the breath.

• All breathalyzers must be calibrated on a regular basis and the breathalyzer calibration logs can be subpoenaed in order to verify the accuracy of the device used against you.
• In order for a breathalyzer to function properly, it must measure blood alcohol content from air in your lungs, not air in your mouth. Recent consumption of alcohol can remain in the air of your mouth and that will artificially inflate the reading of your BAC.
• Certain medical conditions such as GERD or acid reflux, or any other condition that involves burping or regurgitation will also artificially inflate the BAC reading on a breathalyzer if the condition occurs within 15 minutes prior to the use of the device.
• If the breathalyzer doesn’t account for breath temperature, then the device can have a wildly inaccurate readings. For example, raising a person’s breath temperature by 0.5 degrees Celsius can make a person with a .03% BAC blow a .09% BAC.

DUI Blood Test

Blood tests are considered more precise than breath tests, but mistakes can still be made. Just like a breath test, there are certain procedures that must be followed when blood is drawn. These procedures are outlined in Title 17 of the California Code of Regulations. Factors that can affect the accuracy of the blood sample include:

• Technicians are supposed to use a non-alcohol based sterilizer so that blood draw isn’t contaminated with extra alcohol.
• Special preservatives must be added to the blood sample to keep it available for analysis over a period of time.
• The police must store the blood sample correctly and make sure the chain of evidence is always documented.

Blood draws can be forced by police officers when individuals refuse to submit to a chemical-tests. This could lead to a terrible situation for the defendant because he’ll be charged with a refusal and risk losing his driver’s license for one year, and at the same time, the prosecution will have evidence of his blood alcohol level. In other words, if a blood draw is forced, it does not eliminate charges of a chemical test refusal.

No matter what police agency arrests the defendant, all blood samples are stored and analyzed by technicians at the Sheriff’s Office. Sometimes, those technicians make mistakes in the analysis of your blood. The Law Offices of Fred Thiagarajah can request the judge to order that your blood sample be retested by an independent laboratory. This retesting is known as a “blood split” because the independent lab will split the blood sample into two parts. One part will be analyzed for alcohol content. The other part will be analyzed to make sure the proper preservatives were added to the blood. If the proper preservatives were not added to the blood sample, then the entire blood sample is useless and the prosecution cannot rely on your original blood results.

The Right Attorney

You want an attorney that is current on the research and law regarding DUIs. With criminal defense offices in Newport Beach, Riverside and Beverly Hills, Fred Thiagarajah has DUI defense experience in Orange, Riverside and Los Angeles Counties.