How do police determine sobriety of a driver?

How Do Police Determine If a Driver Is Under the Influence?

police determine if driver is under the influenceWhen a driver is under the influence of alcohol, has a blood alcohol concentration level (BAC) of .08% or more, and/or is under the influence of any controlled dangerous substance, they can be charged with a DUI/DWI. A police officer who needs to determine sobriety will need probable cause to arrest for DUI/DWI and also to request a person submit to a chemical test.  

The police can use a blood, breath, or urine test to scientifically measure the levels of alcohol or a controlled dangerous substance in your body. How police determine sobriety of a driver may be a field sobriety test. These tests are often used, but scientific evidence is vital for DUI/DWI convictions. 

And while you are legally able to refuse a chemical test, your license will be suspended for six months when you do, but you legally can refuse.

If you appeal your license suspension within 30 days of your arrest, your suspension is stayed and you can challenge the suspension later in court. Also, in many instances, if you are not found guilty on the criminal side, your suspension is dismissed. That is why it is crucial to contact an experienced DUI/DWI lawyer quickly. 


Chemical Tests for DUI/DWI

Blood alcohol concentration level is most often what police are testing for when a DUI/DWI is at stake. Blood tests are preferred as they inform the police officers of what is in your blood at that moment, while a urine test will inform the officers of what has been in your body in the last few days. BAC levels can be determined by a breath or blood test. 

Breathalyzers are the most common chemical tests police use to determine whether or not a driver is under the influence. A person will exhale into the test chambers to determine the amount of alcohol that is present in the person’s body, based on weight and grams of alcohol per one hundred cubic centimeters of blood. 

Chemical tests determine whether or not the person has any drugs or alcohol in their system, which can warrant a charge. While urine tests will only identify if certain drugs are in an individual’s system, breathalyzer and blood tests can identify the precise blood alcohol level at that moment. A BAC level of .08% or greater is sufficient grounds for a person to be charged. For underage drinkers, .02% or greater is the BAC level that determines impairment for charges. Drug charges are harder to prove because there’s no presence level in the test and trace amounts of drugs can be identified from several days or weeks before the incident. 


Field Sobriety Tests

A field sobriety test is another way that police determine if a driver is under the influence. These are typically three-part tests. A standard field sobriety test includes the walk-and-turn test, the one-leg standing test, and the horizontal gaze nystagmus test. 

The walk-and-turn test and the one-leg standing test help police check your balance and evaluate your drug or alcohol impairment. The horizontal gaze nystagmus allows police to check for eye-jerking and a lack of smooth pursuit when following an object left and right.


Refusing to Take Tests

Chemical tests and field sobriety tests can be refused by the driver when a police officer asks. Field sobriety tests can be refused without any punishment, due to the lack of scientific evidence for proving the amount of alcohol or drugs in your body. However, with the refusal of a chemical test (blood, urine, or breath), you will face an automatic license suspension. 

As an alternative to refusing a chemical test, a driver can ask to take a test at the police station rather than on the side of the road. Refusing to take a chemical test is punishable due to the implied consent law. Implied consent states that as a driver on a public road, you consent to take a field sobriety test or a chemical test if you are suspected of being under the influence.


DUI/DWI Punishments in Louisiana

DUI and DWI convictions are taken seriously in Louisiana, and there are severe consequences. The outcomes you face vary based on your criminal history, age, BAC level when tested, and any other crimes you may have committed during the incident.

Your first and second DUI/ DWIs are misdemeanors, and the third and following DUI/DWIs are felonies. For each DUI/DWI, you face the possibility of jail time, fines, probation, community service, license suspension, ignition interlock devices (IIDs), and more. 

For the exact punishment that you may face in your unique situation, consult with a top DUI/DWI lawyer who can guide you throughout the process.


How a DUI/DWI Lawyer Can Help

When you are facing a potentially life-changing DUI/DWI conviction, you need a top DUI/DWI lawyer by your side to stand up for your rights. The Johnson Firm will fight to reduce and  eliminate your penalties and lead you on the path to a successful outcome. We can answer all of your questions, including how police determine if a driver is under the influence.

Our team will diligently investigate and work to get the best results possible for your DUI/DWI case because we care about your future. We question your charges, find potential flaws, and gather relevant evidence to support each argument. We help you win justice and exercise your rights in every way possible.


Contact The Johnson Firm for Your Consultation

If you’re ready to talk to our team about your case, we’re ready to schedule your consultation. Our team will sit down with you to discuss all of the details, analyze potential outcomes, and plan your path forward. We are here to fight for you until your case is settled.

Call 337-427-8961 or send a message to talk with us about your case and schedule a consultation with a top Lake Charles defense lawyer now!

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