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What Are Other Common Defense Strategies Used in DUI Trials?

Interviewer: Are there any other extremely common defenses that are commonly incorporated?

The Science Doesn’t Match the Facts: Attorney Sloan Frequently Disproves the Validity of the Chemical Testing to the Jury

Brian Sloan: The primary defense that I end up arguing in trial is that basically the blood test machine, the breath test machine, and the machine that tests urine are scientifically flawed; that they should not be relied on by the jury. There are too many issues with how the testing is done. There’s too many issues with the procedures used to test the blood, breath, or urine.

Many times, the argument comes down to the signs just doesn’t match the facts. The sign said that someone is four times the legal limit, but the facts don’t show that my client was four times the legal limit. Now, someone who’s four times the legal limit should be “falling down drunk.” They should be slurring their speech. They should have a flushed face, and bloodshot watery eyes, urinating on themselves and throwing up, or on the ground in a fetal position.

If my client isn’t doing any of those actions, something doesn’t make sense. That tends to be my argument at trial, that the science just simply does not match the facts. The jury duty is to ensure that the prosecutor has proved their case beyond a reasonable doubt; the prosecutor has to leave the jury firmly convinced in the defendant’s guilt.

Attorney Sloan Argues to Instill Reasonable Doubt in the Jurists’ Minds

Their job is not to decide which one is correct, the science or the facts? The jury simply needs to ask themselves, “Is it possible that the science is wrong?” If the facts don’t match the signs, my argument to the jury is that, obviously, it’s possible because something doesn’t make sense here. If something doesn’t make sense here, that is reasonable doubt.

Are Expert Witnesses Commonly Incorporated into a Defense against DUI Charges?

Interviewer: How about expert witnesses? How often do you bring them in? What kind of experts do you bring in?

Attorney Sloan Only Calls an Expert Witness When Appropriate

Brian Sloan: I rarely use expert witnesses. I think it takes a very special case that would need an expert witness to come in and testify. Personally, I think that jurors are not a fan of expert witnesses.

They do have their place. If I have the right type of case, I have no problem bringing in the expert witnesses that I need. I’m able to talk to expert witnesses and retain them if necessary, but I rarely use that myself.

The Prosecution Will Often Call an Expert Witness to Testify

Interviewer: Does the state bring in them commonly, or is it pretty rare that the state that will bring them?

Brian Sloan: The prosecutors always bring in expert witnesses in the form of criminal lists. The scientists that they use to test the blood, breath, or urine, will come in and testify to the procedures that they did and to the results of the blood, breath, or urine test.

By Cross-Examining the State’s Expert Witness, Attorney Sloan Saves His Clients Money and Is Able to Generate the Results He Needs for the Defense

Most of the time, I am able to ask the criminal list questions and get the responses that I want so that I don’t have to bring in my own expert witness. I ended saving my clients money because I’m not willy-nilly hiring expert witnesses, charging my clients additional money just to get information that I can get out of the prosecutor’s witnesses, which my clients don’t have to pay for.

Attorney Sloan Only Calls on Expert Witnesses to Explain Factors of the Case to the Juries when the Information Required Is out of the Realm of Common Knowledge

Interviewer: Even though you rarely call on them under what circumstances have you had to use expert witnesses?

Brian Sloan: I think it’s more common in drug cases and medication cases. Alcohol is usually within the realm of a juror’s common knowledge. They understand the concepts of being drunk. You drank alcohol, and maybe it impaired you.

Medication and drugs and how it interacts with a person’s body, that tends to be a little bit more foreign to people. They don’t quite understand that, so I think the most likely scenario where I would end up using an expert is possibly where there is a case or an allegation of driving under the influence of marijuana.

An Expert Witness May Be Used to Explain How Long the Marijuana Metabolite stays in a Person’s System

If the marijuana levels are low enough, there is scientific literature that says that a person can have active marijuana in their system despite not smoking it themselves. Simply being around with people that are smoking marijuana can lead to marijuana being ingested, secondhand smoke into your body. That will show up with post test results if some were to run a test for THC or for metabolites.

Inactive Marijuana Metabolites Can Be Detected in a Person’s System for a Month

Active THC can be in a person’s system for about a day or two. The inactive marijuana metabolite can stay in a person’s system for up to about a month. Either of them are illegal for a person to have in their system, but if you have a very little level of active THC or inactive marijuana metabolite, it is possible that you got that in your system because you were in the company of people that were smoking marijuana.

Now, generally speaking, even if you are not actively participating in illegal conduct, you really shouldn’t be around people that are participating in illegal conduct.

Arizona Has Passed the Medical Marijuana Law

However, Arizona did pass a medical marijuana law. Under that law, there is a specific provision that says that if a person is around someone who is utilizing their medical marijuana license and they’re smoking marijuana, that a person who does not have a medical marijuana card does not have a duty to run away. They don’t have to leave the area simply because their friend smokes marijuana under the provision of their medical marijuana card.

Then it becomes a defense that, “Look, my client was absolutely entitled to be in the company of his friend, who has a medical marijuana card. And when you are with someone who has a medical card and they’re smoking marijuana, it is possible for my client to get active THC in their system and metabolize into inactive THC.” That is a concept that I think is more scientifically relied upon. You need to cite literature, and for that you need an expert.

By Brian Douglas Sloan

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Brian Douglas Sloan


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Best DUI Lawyer in Phoenix

Why DUI Attorney Brian Douglas Sloan?


19+ Years SOLELY Focused on DUI Defense


4,200+ DUIs Successfully Defended

Top Accolades

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

  • Top 10 in Arizona

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Top One Percent in the Nation

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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

DUI Attorney

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