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What Is the Purpose of Field Sobriety Tests?

Interviewer: In Maricopa County in Arizona, what are the top most common field sobriety tests that have been conducted by police officers?

Brian: Field sobriety tests are basically used by the officer not to try to help you but to try to hurt you. The police try to provide evidence to use court against a person in a DUI case.

However, the officer will often say that they want to utilize field sobriety tests with the suspect to try and make sure that they’re safe to drive and to ensure that they can properly drive home.

The Results of the Field Sobriety Tests Can Be Used as Evidence to Prove You Were Driving While Intoxicated

This is basically a trick an officer uses to try and encourage someone to give them evidence to use against them in trial. In Arizona, there are standardized field sobriety tests. They are not usually utilized correctly.

How Does the Horizontal Nystagmus Test Prove Intoxication?

For example, the Horizontal Nystagmus test is usually referred to as a field sobriety test. It is using a pen or small flash light to go back and forth in front of the eyes to see if the eyes jitter. The officer will often find six out of six cues of impairment.

The cues that the officer is looking for is to see if the left eye does not follow smoothly. They look to see if the right eye does not follow smoothly, as well as if there is distinct and sustained nystagmus at the maximum deviation of the right eye. The officer tries to gauge if there is onset of nystagmus prior to 45 degrees in the left eye and onset of nystagmus prior to 45 degrees in the right eye.

They will also look for vertical gaze nystagmus. However, the Vertical Gaze Nystagmus is not allowed to be mentioned in trial because it has not passed scientific muster.

The Walk and Turn

Interviewer: Besides that test what other tests is a person suspected of driving while intoxicated asked to undergo?

Brian: Besides that test they will do the ‘walk and turn’. This test usually entails having you take nine heel-toe steps forward doing a three-point-turn, and taking nine heel-to-to toe steps back to see if you can properly follow directions.

The officers look to see if you can keep your balance while listening to instructions, if you start before the instructions are finished, and if you stop while walking to steady yourself.

You “fail” the test if you do not touch heel-to-toe and miss by at least a half of an inch and if you lose balance while walking, requiring you to step off the line.

You will also be marked as “failing” if you use your arm for balance six inches or more from the side, if you lose your balance while turning, if you take the incorrect number of steps, or if you simply cannot do the test.

Is it Possible to “Pass” Any of Arizona’s Field Sobriety Tests?

Interviewer: It sounds like anything you do will make you fail the test.

Brian: Yes, pretty much. Anything you do very likely you’re going to fail. No matter how well you think you perform, you are going to fail. And the officers know that. It only takes two strikes against a person for someone to be considered to have failed the test.

You Will Not Be Given Instructions on How to Pass the Field Sobriety Tests, Only on How to Perform Them

The other upsetting part about the test is that they don’t tell you what is going to be a strike against you. They give you the instructions, but they don’t tell you exactly what they’re looking out for.

They don’t tell you that they are going to strike against you for failure to listen to instructions before starting the test. But, they’re going to for doing that if you fail to stand there in place without moving, without stepping off of the line prior to beginning the test and prior to the officer finishing his instructions.

Can You Decline to Perform the Field Sobriety Tests in Arizona?

Interviewer: It sounds impossible to pass which I guess is the point. You’re allowed to refuse the field sobriety test without penalty to you, is that right?

Brian: In Arizona it’s kind of interesting. It’s not clear cut. Basically, Arizona law says that you are legally not allowed to refuse the field sobriety test. However, someone always has the power to refuse. An officer is not going to pull out his gun and put it to your head and say that you have to do these tests.

Declining to Perform the Field Sobriety Tests Can Be Used Against You during a Trial

Now the consequence of declining to perform the test is that your refusal is allowed to be brought up in court as evidence against you. This is done to show that you refused to do the field sobriety test because you knew that you were impaired. That’s why you did not want to do the field sobriety tests.

Interviewer: You can refuse them but they’ll still use it against you in that you knew you were intoxicated. That’s why you refused them.

Brian: That’s how they will try and use it at trial. There was a case about six years ago  that came out and said that it is proper to use this refusal against the person at trial to show proof of knowledge that they were under the influence of alcohol.

By Brian Douglas Sloan

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Brian Douglas Sloan


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Why DUI Attorney Brian Douglas Sloan?


19+ Years SOLELY Focused on DUI Defense


4,200+ DUIs Successfully Defended

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  • Only DUI "Power Lawyer" in the Nation Featured in USA Today, 2022

  • Top 10 in Arizona

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brian sloan on the cover of attorney at law magazine

“I am one of only a handful of Phoenix DUI Lawyers that focuses solely on DUI Defense representation.”

I have spent my entire career SOLELY focused on Arizona DUI Defense Representation, having personally defended more than 4,400 Driving Under the Influence (DUI) clients in the past 19+ years.

If you’re looking for a Divorce Attorney, Tax Attorney, Civil Attorney, etc., I can comfortably say, "I’m not the one for you." I ONLY defend DUI cases in most of Maricopa County, Arizona.

Coming up with traditional, as well as outside-the-box motions and defenses for my clients, often with good results, is the hallmark of my practice.

Lawyers that say they are "aggressive" or "will fight for you" are a dime a dozen. They use these phrases because it is a proven advertising phrase. Being "aggressive" isn’t the same as being good, and is often used to put on a show to hide the fact that they aren’t doing anything meaningful for the client.

The same is true for the Lawyers claiming to do DUI Defense, and Criminal Cases, and Accident Cases, and Divorces, etc. A Jack-of-all-Trades is a master of none! By handling all sorts of cases, they take away from their ability to truly focus on DUIs, and keep up-to-date on the latest changes in DUI Defense Representation.

What I offer is intelligent, quality DUI Defense at an exceptional price. Unlike many other law firms, if you hire The Law Offices of Brian D. Sloan, you actually get me representing you, doing all the work, and working the case. You aren’t hiring one guy with all the experience, but getting the underling with very little knowledge or experience.

I work seven days a week on my client’s cases, and spend hours laying all my thoughts out for my clients in writing, so they can understand their options, and my recommendations. No other DUI Lawyer in the state does this. I try to do what I can to go above-and-beyond for my clients. I hate when the businesses I deal with nickel-and-dime me with hidden costs, and I take pride in not doing that to my clients.

I have not only taught other lawyers how to do DUI Defense Representation at statewide seminars, but I have produced DUI Legal Guides used by defense lawyers across Arizona.

I am one of Arizona's most award-winning DUI Defense Lawyers, as well as being recognized nationally. I was the only DUI Defense Lawyer in the United States named a "Power Lawyer" in a 2022 issue of USA Today

There are no other private Lawyers in Arizona that have personally defended more DUI cases than I have. And as a bonus, I offer a very reasonable flat rate for my legal services, with a payment plan, and without any hidden charges. This guarantees that I offer some of the most competitive rates among all Arizona DUI Attorneys, while being a well-documented and preeminent leader in the field of DUI Defense Representation.

Over the years, countless people have come to me after discovering that their first lawyer made a mistake, gave them false hope or false promises, or simply took their money and didn't do much to advance their case. And you would be surprised at how often this happens.

So, instead of wasting time and money on the wrong DUI Defense Attorney, do yourself a favor and get the proven and well-recognized best DUI Lawyer in Phoenix and the surrounding areas of Maricopa County.

You can reach me on my personal cell phone at 480-720-7839 for a Free ‘In Depth’ Consultation.

I personally defend DUI cases in urban Maricopa County City, Town, and Justice Courts, including:

Ahwatukee / Agua Fria / Arcadia Biltmore / Avondale / Buckeye / Chandler / Country Meadows / Desert Ridge / Dreamy Draw / Downtown / East Mesa / El Centro / Encanto / Gilbert / Glendale / Goodyear / Guadalupe / Highland / Kyrene / Litchfield Park / Maryvale / McDowell Mountain / Mesa / Moon Valley / North Mesa / Peoria / Phoenix / Queen Creek / San Marcos / San Tan / South Mountain / Scottsdale / Tempe / University Lakes / West McDowell / West Mesa / White Tank

For any other Courts in the State of Arizona, including Felony cases, I would recommend my associates on The Arizona DUI Team, whom I work closely with, but I am not the one personally representing the client.

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Brian Douglas Sloan

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