DUI evidence

DUI Field Sobriety Tests

Field Sobriety Tests are a battery of preliminary roadside test that police administer to detect DUI drivers. National Highway Traffic Safety Administration (NHTSA) developed to these roadside tests to be used in early detection of DUI impaired, and DWI drivers. Police officers are formally trained and accredited to administer the tests. They are conducted on the roadside at a DUI stop. The police must have a motorist’s consent of the driver in order to administer them, because they are not mandatory in Arizona.

Standard Field Sobriety Tests
Police officers have been known to conduct other DUI sobriety tests. However, NHTSA has only approved three official FSTs, known as Standard Field Sobriety Tests (SFST):

1. The Horizontal Gaze Nystagmus (HGN);
2. The Walk-and-Turn;
3. The One-Leg Stand.

If any other FSTs were conducted, outside of the SFSTs, your criminal defense attorney can move to have the results suppressed, so the results cannot be admitted as evidence against a suspect.

Consequences of Refusing Field Sobriety Testing in Scottsdale AZ

A driver stopped for DUI investigation, has the right to refuse the FSTs since they are not mandatory in Arizona. However, persons should be aware, that there are consequences of refusal. If you refuse the FST and the police feel they have other “probable cause” to make a DUI arrest, the may proceed with arresting someone on “suspicion of DUI”.

Why You Should Refuse to Take FSTs

Most attorneys will advise you to politely refuse to participate in any Field Sobriety Testing. You have a constitutional right to avoid self-incrimination. In most cases these roadside tests will not serve to help a suspect’s defense, whether they are driving impaired due to alcohol or drugs or unimpaired. There are many reasons for this:

• Historically, and statistically, even the Standard FSTs have proven inaccurate;
• The FSTs are administered, judged, and graded unilaterally by police officer who is trying to arrest you, often resulting in bias or non-objectivity of results;
• Many people unimpaired by alcohol or drugs cannot pass the roadside tests. If the suspect fails, it can be used as evidence against them, even if they were not under the influence of drugs or alcohol;
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• NHTSA rules have strict guidelines regarding instructions and administration of the test; environmental factors; lighting; clothing; landscaping; traffic conditions; candidacy of persons taking it that relate to age, weight, medical conditions and more. If strict guidelines are not followed, the tests results may be invalid;
• They are generally used as evidence against a person and rarely if ever help their defense;
If you have taken or refused a field sobriety test and been arrested for DUI, you should always consult an experienced criminal defense attorney regarding your charges and defense options.

DUI Arrest Based on Blood Test Results Mesa AZ

The police have discretion of whether or not to conduct a blood test or a breath test following a DUI stop in Arizona. Here are 5 reasons why an officer may decide to conduct a blood test over a breath test:

• Breath Test Refusal by the suspect:
• Suspect is not a good candidate;
• Breathalyzer machine non calibrated or in need of repair;
• Police Suspect a motorist is under the influence of chemical or drugs;
• Initial Portable Breathalyzer Test (PBT) was negative for alcohol.

Breath Test Refusal

In Arizona, a motorist has the option of refusing a breathalyzer test. However if they refuse and police believe they have probable cause to believe a person is under the influence of drug or alcohol, they will get a warrant to conduct a blood test. Also, if a suspect refuses the breath test, their driving privileges will be suspended for one year.

Not a Good Breathalyzer Test Candidate
In order for the breathalyzer test to be accurate or valid, optimal conditions must exist. Police must be sure to avoid substance interference. Medical Conditions such as heartburn or gastric reflux disease may skew the results of a BAC reading. Trial results have proven that stomach fluids may find their way into a suspect’s breath such as chewing tobacco; cough drops; belching or vomiting, or even alcohol may cause interference, causing test results to be inaccurate.

Breathalyzer in Need of Calibration or Repair

The official DUI Breathalyzer Intoxilyzer 8000 must be regularly maintained, and records to support its maintenance needs to be kept. Some machines, especially those that have been in use for a while, may have a history or needed repairs, or be in current need of repairs.

Police Suspect Drug DUI

Circumstances may cause the police to suspect a driver is under the influence of drugs instead of alcohol. Some reasons may include a person admits to being under the influence of drugs; the police witnessed a person using drugs; the police saw an illegal drug in plain sight when they approached a vehicle.

Initial Portable Breathalyzer Test (PBT) was negative for alcohol.
Generally, the police will first conduct a Portable Breath Test (PBT). Arizona does not allow the results of the PBT to be used as the sole source of evidence to obtain a conviction. This is because they are not maintained, calibrated, or subject to strict maintenance reporting guidelines like the official Breathalyzer Intoxilyzer 8000 machine. Its main purpose to either show positive or negative for alcohol use. If the results of the PBT are positive the police will proceed with formal breath test. If the results are negative, but police have probable cause to believe a person is under the influence of drugs, they will proceed with a blood or chemical test.

If you wish to defend your DUI charges, blood test, or breath test evidence you should always retain an experienced DUI attorney to represent you.

Articles Tagged with DUI evidence

DUI Field Sobriety Tests (FST): Consequences of a Refusal

DUI evidence: Why Police Did Blood Test v. Breath Test