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The Truth Behind Breathalyzer, Blood, Urine & Field Sobriety Tests

Last Updated on February 12, 2024 by DALA Guest Author

Just because you have been arrested for DUI (driving under the influence) does not necessarily mean you are guilty because the tests came back positive. Here are some reasons why you might have failed these tests and should not have.

The Breathalyzer Test:

Breathalyzers, like any other equipment, must be maintained on a regular basis to ensure their accuracy and functionality. One of these maintenance requirements is the breathalyzer’s calibration. If it is not calibrated properly, the breathalyzer may not give an accurate reading.

Along with the maintenance of the equipment, how the breathalyzer test is given plays a big role in the accuracy of the test. Both these factors can lead to a wrong Blood Alcohol Content or BAC.

There are improper breathalyzer administrations that should be looked into:

Did the police officer wait 20 minutes or more before performing the test?

Did he or she change the mouthpiece before testing you?

Were you requested to take numerous deep breaths and blow as hard as you can into the device?

Did the officer inquire as to whether you used mouthwash recently?

Your attorney will inspect the maintenance records regarding the breathalyzer tested on you and find out if this particular breathalyzer has ever registered false positives in other DUI cases.

Blood Tests:

Blood tests are probably the most accurate form of testing in order to provide an accurate Blood Alcohol Content. This said, there are a number of steps that can taint or compromise the blood samples.

Firstly, did the administrator swab your arm with alcohol first? Also, in order to prevent blood from coagulating, preservatives are added into the tubes that are used. These tubes or kits have an expiration date that must be honored. If a kit was used for your blood test, is there proof that the kit had not gone beyond its expiration date?

Another overlooked issue, on a technical scale, is whether the blood sample taken was mostly plasma or whole blood. This can affect the results of your test. As your attorney, we will review these testing procedures if there are grounds for questionable test results.

Urine Tests and Unrelated DUI Charges:

It’s a fact that water and/or bodily fluids remain in the body for a long period of time. Because of this, urine tests are not as accurate as either blood tests or breathalyzer tests. If your blood alcohol content measures close to or just over .08%, there should be a concern regarding a urine test.

Urine tests, like blood tests, will also detect any drugs a person may have consumed. Even if your tests for alcohol come back negative, if illegal drugs are found in your system you will face charges on driving under the influence. It doesn’t matter if those drugs were consumed two or three weeks ago, you will face criminal charges.

The Field Sobriety Test:

Most law enforcement agencies follow the guidelines of the DWI Detection and Standardized Field Sobriety Testing Student Manual. This manual is published by the National Highway Traffic Safety Administration and should be followed when carrying out field sobriety tests.

Within these instructions, there are multiple situations regarding how and where this test should be given. For instance, what should be done if a suspect tries to balance on one leg or raises his/her arms more than 8 inches and pauses for a few minutes?

The manual states very clearly that the sobriety test should be given on a dry, flat surface or pavement.

As your attorney, we will inspect the area where the sobriety test was performed and review the video footage from the dashboard. By reviewing how the test was given allows your attorney to identify any instructions and/or protocols that were not followed. Should guidelines and procedures not be enforced during the sobriety test, we will request the courts dismiss all charges against you.

Not everything is black and white and not all positive tests mean you are guilty as charged. You should always contact an attorney to be in your corner, especially if you feel you are innocent of these charges.

DALA Guest Author
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