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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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Why Brian Douglas Sloan?
AZ DUI Defense Lawyer Brian Douglas Sloan
  • 13+ Years SOLELY Focused on DUI Defense
  • Represented 2,600+ DUI Clients
    • Regular DUI
    • Extreme DUI
    • Super Extreme DUI
    • Drug/Medication DUI
  • Top One Percent in the Nation"
    National Association of Distinguished Counsel
  • “Top 10 DUI Lawyers in Arizona”
    National Academy of Criminal Defense Attorneys
  • “10 Best Client Satisfaction Award”
    American Institute of DUI/DWI Attorneys
  • Superb “10 / 10” – AVVO.com
  • Preeminent “4.9 / 5.0” -- Martindale-Hubbell
  • “Southwest Rising Star” -- Super Lawyers
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