Idaho DUI Defense

Posted by William Young | Sep 26, 2017 | 0 Comments

There are a number of different defenses that can be utilized by a skillful DUI defense attorney to cast reasonable doubt on any DUI investigation. If you have been arrested for a DUI, you may be extremely worried about the impact it will have on your life. It is important to remember that an arrest does not equal a conviction, even if your BAC was over the legal limit.

Each DUI case is unique, because of this each DUI defense is unique. Call me today for a free case evaluation and to discuss any defenses you may have.

The Traffic Stop: Reasonable Suspicion

The Supreme Court has mandated that in order for a police officer to pull a motorist over for a suspected DUI, the officer must have reasonable suspicion of illegal conduct. However, there is a great deal of disagreement about what constitutes reasonable suspicion that the driver has been drinking. The strength of "reasonable suspicion" varies from case to case but it may be a critical portion of your defense.

Why Were You Stopped?

In order to stop a vehicle, the law dictates that an officer must have “articulable and reasonable suspicion” that the driver is engaging in illegal activity. An officer may not pull a driver over just to check for license and registration; the officer must observe the driver engaging in behavior that indicates that the driver is breaking the law.

In DUI stops, officers can not pull you over just because you were leaving the area of a bar or because it is late at night. This may be their true motivation for a stop but they must rely on some driving behavior. Weaving within the lane over a substantial distance or weaving across lanes are both grounds for reasonable suspicion of DUI. Other reasons include driving too slowly, speeding, failure to signal, car equipment violations, and squealing tires. It is important to note that any of these observed behaviors can be disputed in court.

Many times I have found that the reason for the stop is a loose excuse at best. Driving too slowly can be caused by weather or traffic, weaving within the lane can be explained by ice on the road, there are even times where the listed reason for the stop is flat out false.

The Traffic Stop: Pretextual Stop

A DUI investigation may be performed for many reasons. It is important to challenge the officer's stop to make sure that the reasons listed within a police report were not just a pretext to perform an investigation. In DUI stops, officers can not pull you over just because you were leaving the area of a bar or because it is late at night. This may be their true motivation for a stop but they must rely on some driving behavior.

For instance, during the traffic stop, if the officer sees an open container of alcohol or if the driver exhibits behavior that gives the officer probable cause that he or she has been drinking (slurred speech, glassy eyes, odor of alcohol on their breath, confusion, etc), then the officer may conduct a DUI investigation.

A pretextual stop is a stop that was made for the sole purpose of conducting a DUI investigation. The officer does not care about the traffic violation, they are searching for a reason to conduct a DUI investigation.This is illegal because it circumvents the reasonable suspicion requirement; The officer does not care about the traffic violation, they are just searching for a reason to perform the stop. By following nearly anyone for a long enough period of time an officer is likely to find a driving violation of some sort. A pretextual stop can lead to many different types of investigations including Driving Without A License, DUI, Drug Offenses, etc.

Many times we see people charged with DUIs who were never even told the reason they were pulled over. They may have a defense. If the stop is considered illegal than any evidence obtained would be "fruit of the poisonous tree" - in essence, the BAC results obtained after the stop can not be used against the driver at trial.

If you think you case involves a pretextual stop, call me to discuss the case. A simple conversation may end up being the difference between a dismissal and a conviction.

For more information, take a look at the blog article I wrote on this subject: Pre-textual Stops.

The Traffic Stop: Roadblock or Avoidance Of A Roadblock

Police departments have to follow certain protocols in order to conduct a roadblock. These are constitutional requirements and, if they are not followed, this can constitute a defense as the entire stop may have been illegal.

If you make a turn on to a side street or make a U-turn right before a roadblock, a police officer may suspect that you are attempting to avoid the checkpoint and pull you over. However, in order to stop you, the officer needs to have a reasonable, articulable suspicion that you are avoiding the stop and not making a legitimate turn. You may have needed to turn around because you forgot something or turned onto a side street because that was the direction that you needed to go. If you didn't commit any traffic infractions while making the turn, then there may be no reason for a law enforcement officer to pull you over.

Officer Confirmation Bias

Officer's often have bias towards seeing indications of a crime when they just simply are not there. They want to see them and so they do. They want red eyes to indicate intoxication so they don't allow for any other possibility.

Confirmation bias is defined as: "the tendency to interpret new evidence as confirmation of one's existing beliefs or theories." In criminal investigations this is the tendency of law enforcement to interpret new information in a way that conforms with their pre-existing beliefs about the case. Confirmation bias will causes investigators to ignore evidence that that conflicts with or challenges their pre-existing theory of the case, to discount the importance of new information unless it conforms with their beliefs, fail to properly investigate leads that they believe are unnecessary, eliminate suspects without proper investigation because they like the individual or believe someone else is responsible, and accuse suspects without sufficient evidence because they dislike the individual or have a "gut feeling" about their guilt.

Conformation bias occurs to some degree in nearly every criminal investigation. An experienced DUI defense attorney will work to expose any police bias in regard to your case.

Take a look at my blog article on this area for more information: Confirmation Bias.

Indicators Of Intoxication

Pursuant to Idaho law, officers must have 3 indicators of intoxication in order to initiate a DUI investigation. The first is almost always "driving pattern" (the reason you are pulled over). The two additional indicators can be anything that makes it more likely you are under the influence of alcohol, drugs, or other intoxicating substances. The three most common indicators listed by officers as reasonable suspicion to believe a driver may be intoxicated, and to begin a DUI investigation, are Odor Of Alcohol, Slurred Speech, and Bloodshoot/Red/ Watery Eyes. However, these are flawed indicators and may not actual indicate intoxication.

Indicator: Odor Of Alcohol

The presence of alcohol on a motorist's breath is among the first indications a police officer has that the driver may have been drinking. Officers use this clue to help make the initial determination that the driver is intoxicated and as a basis for beginning a DUI investigation. The odor of alcohol will be noted in the officer's arrest report, serving as evidence in the State's case against the driver.

Odor of Alcohol is Subjective.

Although the odor of alcohol is commonly cited by police officers in arrest reports, it is, in fact, a subjective observation that may not stand up in court. There is tremendous room for human error in detecting the odor of alcohol, as no equipment is used to measure the odor that an officer claims to have smelled at the time of the arrest— it is simply his or her perception of the scent that is noted in the arrest report. Even an experienced officer can not determine someones BAC by the odor of alcohol.

Indicator: Slurred Speech

Officers often cite a driver's “slurred” or “incoherent” speech as a contributing factor in making a DUI arrest. This entry in an arrest report will be used by the State in building a case against you. The presence of slurred speech alone is not grounds for a DUI arrest.

Causes of Slurred Speech

Although alcohol and drug use can cause speech to be slurred, other factors can affect a person's speech pattern. Stress can greatly impact an individual's speech. Certainly, being pulled over and questioned on suspicion of DUI is a stressful event and could result in speech that seems slurred. Fatigue can also impact a cadence of speech, making a person's speech sound slurred. A person may simply have a slow rate of speech or speak with an accent. When a DUI investigation involves an accident, a head injury, shock, or adrenaline can also cause slurred speech.

Indicator: Bloodshot/Watery/Red Eyes

Officers often cite a driver's bloodshot, watery or red eyes as one of their first clues that a driver was intoxicated.

Causes of Bloodshot, Watery, or Red Eyes

Although alcohol consumption may cause an individual's eyes to redden or tear up, unrelated factors may have the same effect. Allergies, exposure to the sun, pollution or smoke and even fatigue can contribute to a person having bloodshot, watery or teary eyes. Some people have eyes that are naturally red or bloodshot. Unless the officer has met the driver before and knows what he or she looks like both sober and intoxicated, any statement about the driver's appearance being indicative of intoxication is just conjecture.

Challenging "Intoxication Indicators"

A skillful DUI defense attorney will know how to cast reasonable doubt on the arresting officer's claim that a the driver was displaying signs of intoxication at the time of their arrest.

Video And/Or Audio

A skilled DUI attorney will review all audio and video evidence to ensure that the officer's report actually matches the facts. There is no need to challenge why a defendant's eyes were read at the time of the stop if when looking at the video that is not the case. Don't assume the video or audio will only support the officer's version of events, in some cases it is the most powerful tool the defendant has to prove their innocence.

Cross Examination

In cross-examining the officer, a skilled DUI attorney will establish that the officer had never heard the defendant speak or saw his behavior before the time of the arrest. Doing so establishes that the officer had nothing to compare the driver's speech pattern or behavior to—whether his or her speech/ behavior was differed at the time of the arrest from any other occasion.

Cross examination will also include the defense attorney reviewing other portions of the arrest report, including the many questions the arresting officer asked the driver. Reviewing these questions serves to establish that the officer was able to understand and accurately record the driver's answers. This may prove that the speech was not a slurred as the officer would like the jury to believe.

Field Sobriety Tests (FSTs)

Often, in order to determine if you are driving while intoxicated, a police officer will have you perform a number of field sobriety tests. Field Sobriety Tests (FSTs) are used by law enforcement officers to provide probable cause to initiate a breath or blood test.

There are three FSTs that officers commonly utilize during a DUI investigation: the Horizontal Gaze Nystagmus (HGN), the Walk-and-Turn (WAT), and the One-Leg Stand (OLS). These are the only three field sobriety tests endorsed by the National Highway Traffic and Safety Administrations (NHTSA), thus they are referred to as "Standardized" Field Sobriety Tests.

Although considered standardized, these tests have been widely criticized as designed to fail. There are many factors that can affect a driver's performance on the FST's: age, injury, or disease, an uneven surface, poor footwear, eye conditions or diseases that affects their ability to follow the object, etc. Any of these factors could lead an officer to improperly conclude that you are impaired. Even under perfect conditions a sober driver would have difficulty passing these tests.

Horizontal Gaze Nystagmus

This is an involuntary jerking of the eye that occurs when the eyes move from side to side. The test requires the driver to look forward at a small object, usually the officer's finger, pen, or a small flashlight and follow the object with their eyes as he moves it side to side. The drivers head is to remain still during the test. Officers look for three indicators of impairment when administering this test:  1) an inability to follow the moving object smoothly; 2) distinct eye jerking when the eye is at maximum deviation (the point at which the eye has moved fully to one side); and 3) whether the jerking of the eye is within 45 degrees of center.  


This tests the driver's ability to complete tasks with divided attention. Law enforcement officers believe that the inability to perform a task that requires divided attention is a sign of intoxication. During this test, the driver is instructed to walk, touching heel-to-toe on each step, along a straight line, turn, and walk the straight line back to the start. The officer will look for several indicators of impairment: 1) if the driver cannot keep their balance; 2) walking before the instructions are finished; 3) stopping in the middle of the test; 4) failure to touch heel-to-toe; 5) steps off the line; 6) takes the wrong number of steps; and 7) makes an improper turn.

One-Leg Stand

This is also a divided attention test.  The driver is instructed to stand with one leg in the air approximately six inches off the ground while counting to a certain number. The officer looks for indicators of impairment, including: 1) swaying; 2) difficulty counting; 3) using their arms to keep balance; and 4) putting the foot down.

An experienced DUI attorney will be able to show how difficult these tests are to pass, even sober, and what factors the officer failed to take into account when administering the tests.

Breath and Blood Testing

There are frequent problems with the tests used in measuring a person's BAC. An experienced DUI attorney may be able to challenge the results of these tests.

Breathalyzer Test

If you are pulled over and suspected of Driving Under the Influence (DUI) in Idaho, the most common method used to determine Blood Alcohol Content (BAC) is the breath test.

Breath tests are considered reliable enough to stand up in court, but that doesn't mean they don't come with a margin for error. If drivers are tested and the results are close to the legal limit, DUI attorneys can often argue that the machine gave an incorrect reading, and therefore help your case. 

Breath test machines must be properly maintained with regular accuracy checks and calibration.  Failure to do so will result in the breath test machines giving inaccurate test results.  Proper records must be kept if the test results are to be used against you.

Portable vs Stationary Breath Machine

There are many differences between the types of machines used to determine BAC. Each of these has their strengths and weaknesses. A skilled DUI attorney will be able to point out the flaws of the machine used in your case for determining BAC.

Blood Test

Blood tests are not the most frequently-used tests due to their complex processing requirements, but they are known to be the most accurate in determining the exact amount of drugs and/or alcohol in a driver's system.

Proper blood draw procedures must be followed if a blood test is given and the blood vial must be handled properly during the period prior to the testing or the BAC result will not be accurate. Blood is often shipped from location to location, leaving a lot of room for mishandling and contamination. Proper handling procedures, documenting chain of custody and preventing contamination, must be followed if the test results are to be used against you.

Unlike a breathalyzer, or a blood test for alcohol, blood testing for medications or drugs is a very accurate way to show that a substance is present in someones blood but it does not provide us with any other information. Certain drugs and medications will remain in your blood for long after you take them and long after any effects have worn off. Your body slowly filters out any presence of these substances over time. The classic example of this is marijuana which can be tested for weeks after ingestion. Essentially, all a blood test tells us is that at some point the individual came into contact with the tested substance.

Warrantless Blood Testing and Implied Consent

The recent United State Supreme Court decision in the case of Birchfield v. North Dakota, may have an impact on your case, depending on the circumstances. That case involved a man who refused to submit to a blood test to determine his blood alcohol concentration. At the time, as in many states, North Dakota law made it illegal to refuse a blood draw. The law said that by driving on state roads the driver implied consent for the taking of a blood sample. The Supreme Court overturned these laws. It said that a blood test is so invasive that it requires express consent or a warrant.

BAC - Breath and Blood Testing

Can The Police Draw Blood Without Permission?

Blog Article About A Recently Won DUI Case Involving Blood Evidence

A skillful DUI defense attorney will know how to cast reasonable doubt on the accuracy of the blood or breath test results.

Refusal Of Breath Testing

According to Idaho law, you have the right to refuse the breathalyzer. Many people believe this will make it harder for the State to convict them of a DUI or that a blood test will somehow “prove” they were under the legal limit. This may not be the case, See: Should I Refuse The Breathalyzer?

If an officer determined that you refused to take a test, you can challenge this determination if you did not actually intended to refuse.

For more information take a look at my blog article on this subject: Should I Refuse The Breathalyzer?

Drug Recognition Experts

A Drug Recognition Expert (DRE) is a law enforcement officer trained to identify people whose driving is impaired by drugs other than, or in addition to, alcohol. The 12 step procedure they follow is called a Drug Influence Evaluation (DIE), to determine which category of drugs is causing the driver to be impaired.

If a DRE determines that a driver is impaired, they will look for indications of the drugs by the common perceivable effects the drugs have on the human body. There are seven categories of classifications a DRE is looking for, including: Central Nervous System (CNS) Depressants, CNS Stimulants, Dissociative Anesthetics, Cannabis, Hallucinogens, Inhalants, and Narcotics.

Truthfully, the "expert" part of Drug Recognition Expert is a misnomer, these are people who are trained to fill out a chart based upon what they see. The chart is supposed to tell them what substance is present. The DIE is a guess! It is subjective and easily manipulated. DREs are not doctors, they have not nurses - in fact, they have little to no medical training at all. The DIE is nowhere near 100% accurate and there are many ways to challenge the DRE's testimony.

 For more info, see: Drug Recognition Experts OR

About the Author

William Young

Idaho Criminal Defense and Trial Attorney. I was admitted to the Idaho State Bar in May, 2014, and for the next 4.5 years I practiced as part of Peterson Lawyers with the father-daughter tandem of Chuck Peterson and Courtney Peterson. They were great mentors to me and I still consider them among...


There are no comments for this post. Be the first and Add your Comment below.

Leave a Comment

Free Consultation

Each case is unique. The strength and weakness of your case will depend on the particular facts of your case. Contact us for a free consultation. We will answer any questions you have, and give you an honest assessment of your case.

Committed To Every Client

We are committed to providing every client with respect and compassion they deserve; Every case will receive our full attention and passion. We work one-on-one with every client to make sure you get the best defense possible.

Copyright © 2020 William Young and Associates

The information on this website is for general information purposes only. Every case is different, nothing on this site should be taken as legal advice for any specific case. Viewing the information contained on this site does not constitute an attorney-client relationship.