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Arizona DUI Defense Attorneys

More than ever, Arizona DUI laws, the science underlying DUI prosecutions, and potential defenses have become increasingly complex.  The Nolan Law Firm can help.  Mr. Nolan will personally, thoroughly, and aggressively investigate your defenses.  Being charged with a DUI offense is often an overwhelming experience, but it does not have to ruin your life!

Remember, at the very least, the United States and Arizona Constitutions afford you rights that are worth defending.  Your freedom is worth protecting.  Your peace of mind is worth preserving.  Your chances of being convicted are 100% if you run down and plead guilty without discussing your potential defenses with an experienced and aggressive attorney. Call The Nolan Law Firm now or contact us for a free consultation about your defenses.

In Arizona, defending against DUI charges starts by considering whether any of the following defenses potentially apply to your case.


Whether as a pedestrian or as a driver, when can a police officer lawfully stop you?  The answer under the Fourth Amendment to the United States Constitution is that police cannot stop you unless, under the totality of the circumstances, they have a reasonable suspicion that you are engaged in criminal activity, or probable cause to believe you have committed a traffic violation.

a)      National Highway Traffic Safety Administration (“NHTSA”) Nighttime Driving Cues – Officers frequently rely on their purported observation of one or more of the NHTSA nighttime driving cues to justify a DUI traffic stop.  Through NHTSA studies, researchers published The Visual Detection of DWI Motorists brochure to assist officers in detecting impaired motorists.  The brochure details twenty-four (24) cues that supposedly correlate to a probability that a driver may be DUI.  Researchers divided the twenty-four (24) driving behaviors into four (4) categories:  (a) problems in maintaining proper lane position; (b) speed and braking problems; (c) vigilance problems; and (d) judgment problems.  Using these cues, an officer will predict a driver is DUI at least thirty-five percent (35%) of the time.  See also The Detection of DWI Motorcyclists.    The bottom line is that officers frequently misidentify driving behaviors as one of the NHTSA nighttime driving cues.

b)      Traffic Violations:  Although Fourth Amendment jurisprudence establishes that a law enforcement officer may stop you for committing a traffic violation, the officer’s discretion to do so is limited.  Consider, for example, State v. Livingston, 206 Ariz. 145, 75 P.3d 1103 (Ct.App. 2003), where an officer violated the Fourth Amendment by stopping a driver for once crossing a lane divider.  The officer attempted to justify his stop by arguing that the driver violated A.R.S. § 28-729(1) by failing to drive “as nearly as practicable” within a single lane.  The Arizona Court of Appeals condemned the traffic stop as an unreasonable violation of the driver’s Fourth Amendment rights.  Just because an officer claims to have observed you weave once or momentarily straddled a lane divider or turned wide, does not mean that you have automatically committed a traffic violation.

c)      Anonymous Tips:  Traffic stops premised upon anonymous tips are suspect.   At a minimum, anonymous tips must include either private information about the driver or a prediction of future conduct that were corroborated by the police.  To justify the stop, the State must demonstrate the reliability of the anonymously-provided tip.  This means the State will have to show that (1) the tip gives sufficiently detailed circumstances to indicate that the informant reliably obtained the information; or (2) the officer made independent observations corroborating the information in the tip.  To satisfy its burden of proof, the State must prove that the tip contains more than would otherwise be known by any member of the general public.

2.      No Reasonable Suspicion to Perform Field Sobriety Tests (“FSTs”)

Following the traffic stop, does the officer have a reasonable suspicion to conduct Field Sobriety Tests?  In Arizona, FSTS are a limited search.  As such, the Fourth Amendment requires the officer to have reasonable suspicion to believe that you are impaired before administering FSTs.  To this end, the officer will consider your driving behavior and look for signs or symptoms of alcohol and/or drug consumption, including but not limited to the following:

  • bloodshot and watery eyes
  • slurred speech
  • fumbling with your wallet or documents
  • admitting you consumed alcohol and/or used drugs
  • stumbling or staggering
  • odor of alcohol
  • flushed face
  • using your car door for balance
  • mood swings
  • swaying

Based upon the totality of the circumstances, the officer will have to make a judgment call about whether reasonable suspicion exists.  Your driving behavior coupled with the presence or absence of these factors can make all the difference.  For example, if the officer stopped you for weaving across four lanes of traffic, and noted all of the above signs and symptoms of alcohol consumption, the officer likely had sufficient reasonable suspicion to conduct FSTs.  If, on the other hand,  the officer stopped you for speeding and detected the odor of an alcoholic beverage, you can persuasively argue that the officer lacked reasonable suspicion to conduct FSTs.

Warning:  You should always decline to perform FSTs until after speaking with an attorney.

3.      No Probable Cause for Arrest

Where does the phrase “probable cause come from?  The answer is the Fourth Amendment to the United States Constitution, which guarantees:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

Thus, it is well settled that police cannot arrest you without probable cause.

What does “probable cause to arrest” mean?  This means that the officer has a reasonable belief that a person is committing, has committed, or is about to commit a crime.  The test to determine whether probable cause existed for your arrest is whether the facts and circumstances within the officer’s knowledge are sufficient to warrant a prudent person to believe you committed, were committing, or were about to commit DUI.  If the officer lacked sufficient objectively reasonable facts to believe you were DUI, then he violated your Fourth Amendment rights.

Under Arizona DUI law, you should also consider, where appropriate, challenging the officer’s basis for arresting you for DUI in a few specific instances:

a)      Actual Physical Control (“APC”):  In any DUI prosecution, the State must prove that you were driving or in actual physical control of a motor vehicle.  “Actual physical control” refers to whether under the totality of the circumstances shown by the evidence, your current or imminent control of your vehicle presented a real danger to yourself or others.  Factors to be considered may include:

  • Whether the vehicle was running;
  • Whether the ignition was on;
  • Where the ignition key was located;
  • Where and in what position the driver was

found in the vehicle;

  • Whether the person was awake or asleep;
  • Whether the vehicle’s headlights were on;
  • Where the vehicle was stopped;
  • Whether the driver had voluntarily pulled

off the road;

  • Time of day;
  • Weather conditions;
  • Whether the heater or air conditioner was


  • Whether the windows were up or down;
  • Any explanation of the circumstances shown by the evidence.

Many Arizona DUI attorneys choose to raise this issue for the first time at trial.  The more aggressive approach, however, is to file a pretrial Motion to Suppress arguing that the officer lacked probable cause to arrest you for DUI because you were not in actual physical control of your vehicle.  If the motion is unsuccessful, you can still raise the defense at trial.

b)      No Witness Can Place You Behind the Wheel:  If the officer did not see you driving and the State does not have a witness that will testify that you were driving, then you should absolutely file a pretrial Motion to Suppress arguing that the officer lacked probable cause to arrest you for DUI.  As noted above, if your motion is unsuccessful, you can still raise the defense at trial.

4.      No Corpus Delicti

What is corpus delicti?  Corpus Delicti is a principle of law that requires the State to prove that a crime has occurred before the State can convict you of committing a crime.  The State may establish corpus delicti by circumstantial evidence.  As a matter of law, however, you cannot be convicted of DUI based solely upon your out-of-court confession to DUI.  This doctrine most frequently applies where you have been involved in an accident, no injuries are involved,  you are out of your car when the officer arrives, and subsequently, you tell the officer that you were driving.

Warning:  If you tell an officer that you were driving a vehicle that was involved in an accident resulting in injury to or death of any person, your statement is admissible in any criminal proceeding without further proof of corpus delicti.

5.      Right to Counsel Violation

In Arizona, before deciding whether to submit to a breath, blood, or urine test, as long as it does not unreasonably disrupt the DUI investigation, you have the right to consult with an attorney.  To invoke your right to counsel, the law requires you to make a clear, unambiguous statement demonstrating an immediate desire to speak to an attorney.  Once you have clearly invoked your right to counsel, police cannot interfere with your attempts to contact an attorney.  This means that police must (1) provide you access to a phone and phone book; (2) wait a reasonable amount of time for the attorney to return your call; (3) not refuse to provide a call back phone number for the police station; (4) allow you to receive telephone calls from an attorney returning your call; and (5) upon your request, provide you privacy to speak with your attorney.  Depending on the circumstances of your case, the remedy for a violation of your right to counsel may involve dismissal of the charges or suppression of the evidence obtained by police after violating your right to counsel.

Warning:  If you are arrested for DUI, always request to speak with an attorney before deciding whether to submit to a breath, blood, or urine test.

6.      Independent Test Violation

If you have been arrested for DUI in Arizona, the Due Process Clause of the Arizona Constitution guarantees you the opportunity to obtain independent evidence of sobriety (i.e., an independent chemical test) at the only time it is available.  Your right to an independent chemical test includes both (1) your Due Process right to gather potentially exculpatory evidence, including having a sample of your blood drawn by someone who does not work for the police department, and (2) having a sample of your blood preserved by the State for your own independent analysis.  The police cannot unreasonably interfere with your efforts to get an independent test.  Such interference can occur, if, for example, the police decline to release you for an independent test or deny you access to counsel, if you are unreasonably denied bail, or if the State represents to you that the charges against you will be dismissed and in reliance on that representation, you destroy the independent sample.

Warning:  If you are arrested for DUI, always request that the officer release you for an independent test.

7.      Challenges to Breath Testing

a.)        Admissibility of Breath Tests – Statutory Method.  A.R.S. §28-1323 sets forth five (5) foundational requirements the State must establish before your breath test results are admissible in trial.  These requirements include:

i.)         the Department of Public Safety (“DPS”) approved the breath testing device;

ii.)        the breath test operator possessed a valid permit issued by DPS to operate the device;

iii.)       the breath test operator followed the DPS approved operational checklist;

iv.)       duplicate tests were administered and the results were within 0.02 of each other, or the breath test operator observed you for twenty (20) minutes immediately before the test; and

v.)        the breath testing device was in proper operating condition.

Under the statutory method, the State must be able to establish all five elements in order for your breath test results to be admissible against you.

b.)        Admissibility of Breath Tests – Rules of Evidence Method.  Under this approach, the State must establish by expert testimony that (i) the test is generally accepted in the scientific community and (ii) the test was conducted properly and the results were measured and recorded accurately.  The State typically does not use this approach unless the State is unable to admit your test results through the statutory method.

c.)        Many Variables Can Affect the Accuracy and Reliability of Your Breath Test.  The following is a non-exhaustive list of potential defenses and challenges to breath tests.

  • Invalid or insufficient deprivation or observation period.  Arizona law requires the police to conduct a fifteen (15) minute deprivation period immediately before administering your breath test if replicate tests are administered, or a twenty (20) minute observation period immediately before administering your breath test if only one breath test is given.  The deprivation or observation period respectively is invalid if, during this period, the officer failed to continuously observe you; or burping, belching, vomiting, or regurgitation occurs.
  • Gastro Esophageal Reflux Disease (“G.E.R.D.”).  This may also be referred to as gastric reflux or a hiatal hernia.  Given that being investigated and/or arrested for DUI is extremely stressful, and that some of the most frequent triggers of acid reflux are stress and alcohol, this can be a very powerful defense for people who have this condition.
  • Mouth Alcohol.  Trace amounts of alcohol that are present in your mouth at the time of the breath test can significantly elevate the Intoxilyzer’s measurement of your BAC.  For example, slightly regurgitating can bring up alcohol from your stomach into your mouth, or alcohol can become trapped in pockets around roots, dentures, or bridgework.
  • Elevated Breath Temperature.  If the temperature of your breath is one degree above 34° Celsius, the BAC recorded by the Intoxilyzer could be as much as 8.6% higher than your true BAC.
  • Elevated Body Temperature.  If your core body temperature is one degree above 34° Celsius, the BAC recorded by the Intoxilyzer could be as much as 8.6% higher than your true BAC.
  • Breathing Pattern (failing to immediately exhale).
  • Partition Ratio.  Breath testing devices, such as the Intoxilyzer, assume that there is a direct relationship between the amount of alcohol in both your breath and your blood.  This standard ratio is 2100 to 1, which means that the amount of alcohol in one milliliter of blood is 2100 times greater than the amount of alcohol found in a cubic centimeter of an air sample. Because of this, all breath machines are calibrated based on this 2100 to 1 assumption. However, not all people have this breath to blood ratio. If a driver has a ratio lower than this, his or her breath test result will be artificially high.
  • Radio Frequency Interference.  This occurs when the radio waves from a cell phone, the officer’s radio, or other electronic equipment with surge capabilities, interfere with the Intoxilyzer’s ability to accurately measure your BAC, potentially resulting in an artificially inflated reading.
  • Replicate test results that do not agree within 0.02 of each other.
  • +/- 10% Margin of Error.
  • Drinking after driving ended.
  • BAC is inconsistent with your performance on FSTs.
  • BAC is inconsistent with your drinking history.
  • Diabetes.  If you have diabetes, are borderline diabetic, or are hypoglycemic and consume alcohol in any amount, this can cause your body to convert high levels of acetone into isopropyl alcohol, which can artificially inflate your reading.
  • Coerced Test.  This defense typically arises when the Officer advises you of the Administrative Per Se/Implied Consent warnings, but then crosses the line by threatening to book you into jail, for example, if you do not submit to the test.

8.      Challenges to Blood Testing.

a.)        Admissibility of Blood Tests.  Blood tests are admissible under the same rules and conditions as apply to breath testing, which are noted above.

b.)        Many Circumstances Can Affect the , Admissibility, Accuracy, and Reliability of Your Blood Test.  The following is a non-exhaustive list of potential defenses and challenges to blood tests.

  • No Consent.  Absent a search warrant or exigent circumstances, the police need your consent to draw your blood.  Even then, the State has the burden of proof to show that your consent was freely and voluntarily given.  The State cannot satisfy this burden by “showing no more than acquiescence to a claim of lawful authority.”  State v. Flannigan, 194 Ariz. 150, 153, 978 P.2d 127, 130 (Ariz.App. 1998).
  • Officer Fails to Properly Invoke Arizona’s Implied Consent Law.
  • Qualifications of the Phlebotomist Are Insufficient.  Arizona law requires that blood only be drawn by as physician, registered nurse, or other qualified person.  The State must demonstrate the phlebotomist who drew your blood was competent to do so through training or experience.
  • Blood Kit Contained Expired Blood Tubes or Antiseptic Swabs.  After expiration, the seal on blood tubes is no longer guaranteed.  This is significant because a compromised seal can introduce contaminants into your blood sample.
  • Phlebotomist Improperly Disinfected Your Blood Draw Site.  If the phlebotomist used an alcoholic cleansing agent to disinfect the draw site, your BAC could be artificially inflated.  Also, if the phlebotomist did not cleanse the draw site using concentric circles moving outward from the draw site, then bacteria, such as yeast, may still be present.  If yeast is drawn into your blood sample, this may cause fermentation.
  • Fermentation.  This is a process that occurs when sugars and yeast combine in your blood, whereby the sugars such as glucose, fructose, and sucrose are converted into cellular energy.  The resulting metabolic byproduct  is ethanol.  In other words, fermentation can create alcohol in your blood and artificially increase your BAC.
  • Hemolysis.  This is the breakdown, tearing, and splitting of red blood cells.  Among other things, improper tube mixing, difficult blood draws, unsecure hypodermic needle connections, contamination, and incorrect needle size,  can all cause hemolysis.  And, hemolysis can cause your BAC to increase.
  • “Salting Out” the Blood:  Under some circumstances, if a blood collection tube contains a small amount of your blood or too much anti-coagulant or preservative, the chemicals can salt out your blood, resulting in your BAC being artificially increased.
  • What Did the State Test: Whole Blood, Serum, or Plasma.  A sample of whole blood contains cellular material, including serum and plasma.  In contrast, serum or plasma do not contain cellular material.  The State’s analysis of a blood sample consisting of serum or plasma, therefore, will show a higher BAC than if the State had tested the whole blood sample.
  • Head Space Gas Chromatography.  In Arizona, crime laboratories use Head Space Gas Chromatography to analyze blood for the presence of alcohol.  Chromatography is often referred to as a separation science.  The Gas Chromatograph (“GC”) is supposed to separate substances in your blood and measure them according to their retention time.  If the GC that analyzed your blood cannot adequately distinguish between all of the volatile substances in your blood, or volatile compounds are co-eluting, then the GC is not working properly and your BAC may be significantly inflated.
  • Margin of Error.  In Arizona, blood test results are required to be within a plus or minus margin of error of 5%.
  • Crime Lab Contamination. 
  • Inadequate Chain of Custody Records.  The State is required to maintain proper chain of custody records.  Such records must show the transfer and location of your blood sample from the time the officer/phlebotomist draws your blood to the time the State seeks to use it in Court.  Chain of custody challenges are relevant to the weight and not admissibility of your blood test results.

Just because the State’s breath or blood test reports a high value for your BAC does not mean that your true BAC was actually that high.  Remember that you are constitutionally presumed to be innocent.  So, consider for a moment the possibility that one or more of these factors may have elevated your BAC results and/or may create doubt based upon reason in the minds of your future jurors about the accuracy or reliability of the State’s BAC results, take a deep breath and have hope for a favorable resolution of your case.  An experienced and aggressive attorney can give you the peace of mind you need to function while your case is pending.  The Nolan Law Firm can help.  Call now for a free consultation.

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