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Reliability of Breathalyzers

There are many reasons to refrain from drinking and driving both for your sake and for the sake of other drivers on the road. However, you could be pulled over for suspicion of a DUI even if you have not been drinking. One of the tests that police officers may perform after stopping a vehicle is a roadside breathalyzer test, also known as a preliminary alcohol screening test or PAS test, which measures a person’s blood alcohol level. The results of the PAS test are displayed almost instantly after the PAS test is performed. If a person’s blood alcohol content (BAC) is below 0.08 percent, the legal limit for driving a vehicle, the person will likely be released and not arrested for a DUI. However, if the person’s BAC is above 0.08 percent, this is likely enough for the person to be placed under arrest and taken to the police station for the police to run either a blood or chemical breathalyzer test to confirm the results of the PAS test. The reliability of breathalyzer results are very important and are often the strongest piece of evidence against a defendant as these tests provide concrete, quantifiable proof that a person was impaired. There may be hours between the time when the driver takes the PAS test and when the test is performed at the station. Based on rumors and a lack of understanding as to how these tests work, many people question the reliability of breathalyzers. Indeed, there are many factors that affect the reliability of breathalyzers, therefore if you or someone you know has been arrested for a DUI in Orange County, it is essential that you contact an experienced Orange County DUI attorney as soon as possible to help you with your case.

Are PAS Tests Admissible?

Following a stop by the police for suspicion of a DUI, the most important thing to remember is that you do not have to submit to PAS test. Refusing the PAS test may be helpful to your case and there will not be any punishment for refusal. However, refusing the subsequent chemical breathalyzer or blood test at the police station will most likely result in the loss of your license for a period of one year. If you did not have anything to drink or are reasonably certain that you are under the legal limit, it may be wise to take the PAS test so that you are not arrested for the suspicion of driving under the influence and taken to the station for subsequent testing. Police officers are required under California Vehicle Code Section 23612 to advise drivers suspected of a DUI that they have a right to refuse the PAS test. However, persons under the age of 21 may not refuse a PAS test and if they do, they may have their license suspended for a period of one year. A variety of mistakes can be made throughout the process of an investigation, arrest, and subsequent breathalyzer or blood test searches that can result in unreliable evidence. A lawyer who is knowledgeable on DUI law can help create a defense strategy to try and have this evidence excluded for trial. Therefore if you or someone you know has been charged with a DUI in Orange County, it is crucial you contact an experienced attorney as soon as possible to review your case.

Orange County DUI attorney William Weinberg is an experienced lawyer in Orange County who has many years of experience defending clients charged in DUI cases. He will consider your case free of charge and advise you of your options. To reach him please contact his Irvine office at 949-474-8008 or by emailing him at
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Anyone who is arrested should contact an experienced Orange County DUI Criminal Defense Attorney to determine whether or not their Fourth Amendment rights against unreasonable searches and seizures, were violated.

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