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  • THE REASONABLE SUSPICION/PROBABLE CAUSE DEFENSE: winning the case because the police broke the law --- Was the traffic stop legal?

  • Most people think that the only issue in a drunk driving case is whether the driver was intoxicated. Nothing could be further from the truth. In fact, whether the driver was intoxicated may not matter at all. The first and most important issue in any drunk driving case isn't whether the driver broke the law, but whether the police broke the law. Yes -- you read that right.

  • Many drunk driving cases revolve around the conduct of the police, not the guilt of the driver.  If police obtain evidence of guilt illegally, in violation of the driver's Constitutional rights, then that evidence is not legally admissible and cannot be used against the driver in court.  (This is known as the "exclusionary rule," and it applies to all evidence which is unconstitutionally obtained by police as well as some evidence obtained in violation of state statutes.)

  • For example:  the Fourth Amendment of the United States Constitution does not allow stopping a motorist on a mere hunch.  If a driver were stopped by police merely on a hunch that the driver was intoxicated, all of the evidence derived from that illegal stop would be "suppressed" -- excluded by the judge from evidence because it was illegally obtained.  That means the test results, the "field sobriety tests," and even a driver's statements to the police can all be excluded as evidence.

  • Understanding how a police officer's conduct can affect a drunk driving case is a lot like understanding how a row of dominos might fall.  It doesn't matter where in the row you start knocking down the first domino.  No matter where you start, every domino that follows the first to fall will fall also.  Attacking police conduct in a drunk driving case is similar -- it doesn't matter where in the sequence the officer exceeded his legal authority.  Whatever evidence follows is likely to be excluded because it is tainted evidence -- evidence derived, directly or indirectly, from the officer's unconstitutional or illegal conduct.

  • Police officers cannot stop a vehicle on a mere hunch, and they cannot arrest without "probable cause."  The police must have "reasonable suspicion" to stop a vehicle.  Generally, these are subjective observations by the police based on something unusual about the way a person is driving. This is a very very low standard and it can be satisfied by virtually anything which appears out of the ordinary that might be a sign of a driver being under the influence. A general rule:  if the police want to stop you and investigate something, they will, and justify their actions afterwards.

  • Common things which have constituted "reasonable suspicion" are" license plate light out; brake lights not working; tail light out; headlight out, loud music, apparent underage drivers out late at night; turning to wide, turning to narrow, driving to fast, driving to slow, unusual activity in the car - having sex, and drinking from a shiny container. Basically, the facts supporting reasonable suspicion are only limited by the imagination of the police.  In fact it is not unusual for the police to stop a driver with a license plate light not working, and mysteriously the next day the light starts working again.  In court it is your word against the police.  Judges tend to give the police the benefit of the doubt absent extraordinary circumstances, direct contrary proof, or the officer's bad reputation.

  • If the police stop you for any traffic violation, no matter how minor, it is sufficient to justify the traffic stop.  Once you are stopped, the police must then establish reasonable suspicion that you might be driving impaired.  Some of the more obvious things the police look for are: smell of intoxicants; slurred speech; bloodshot watery eyes; admission to drinking; alcohol containers in the vehicle; and mood swings i.e. laughing one minute and crying the next.  Observation of any of these would establish "reasonable suspicion" for the police to continue the investigation.  The reason a police officer asks you "have you been drinking tonight" is because if he gets a "yes" answer from you, he right then and there has established "reasonable suspicion" merely because you were driving the car and admitted to drinking.

  • In addition, during holiday seasons, police officers typically set up field sobriety checkpoints where they routinely stop every driver who passes through the checkpoint. These checkpoints do not require the officer to observe anything suspicious about a person before stopping and investigating someone.

  • Probable cause to arrest for drunk driving is also required, before a police officer can ask a driver to submit to a blood test. "Probable cause" is an objective standard, one required by the Constitution itself.  An officer's opinion isn't probable cause, and merely consuming alcohol and then driving is not "probable cause" to arrest for drunk driving.

  • Often, police rely on phony evidence to justify an stop.  Police also rely on bogus evidence.  

  • Many police officers use the "finger-to-nose" field sobriety "test."  But the National Highway Traffic Safety Administration (NHTSA) studied "FSTs" in the l980s.  In the first attempt to apply scientific principles to field sobriety testing, the federal government authoritatively determined that no correlation existed between level of alcohol concentration and failure on the "finger-to-nose" test.  No one could do it, even sober.  So, the feds rejected it as a standardized test. 

  • So why do police who know this still use the "finger-to-nose" "test."  Because they know it can't be done.  By using the "finger-to-nose," these police are attempting to create probable cause by relying on a bogus "test."  It is a set up.  They ask you to do a test they know cannot be done and then use it to justify arresting you for DUI.

  • "Field sobriety tests" are themselves something of a police scam.  Standing on one leg is the natural activity of a flamingo, not the human being.  Walking heel-to-toe is inherently difficult and imbalanced, since the human body is designed for walking with one foot in front and to the side of the other.  Police claim these tasks determine intoxication by establishing that a driver has poor balance.  But putting a person into a stance that is inherently imbalanced doesn't measure balance.  What difficulty balancing on one leg establishes is that the driver is human.  That's why police have to practice doing these tests. 

  • All of these issues -- and many more -- can affect whether a stop or an arrest were legal, and whether police evidence can actually be used in court or, instead, must be "suppressed" because it was unlawfully obtained by an illegal stop or arrest.

  • When police break the law, if they act illegally in making a stop, arresting a driver, or requiring a test, that evidence can not be used in court.  No evidence means no conviction. 

  • Never assume a police officer's actions were legal merely because they were the actions of a police officer. Cops are human and they make mistakes, lots of mistakes. It doesn't take much education to be a cop.  "Certification" as a Arizona law enforcement officer requires a high school degree, no felony convictions, and a few weeks of training at a police academy. By contrast, being a lawyer takes four years of college and three years of law school. Lawyers know more about the law than cops do.  An experienced DUI defense attorney knows more about DUI's than the police as well.

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  • The "I WASN'T DRIVING DEFENSE" or actual physical control or apparent ability to drive defense -- If you pulled off the roadway to sleep it off, you may not be guilty of DUI

  • You are driving home after having a few cocktails.  You realize that you have had a few too many and decide to pull off the road to "sleep it off". Depending on the circumstances i.e. where you pull off, what you do with the car, what you do with the car keys, if the car was running at the time the police make contact, you may have a valid defense. 

  • In Arizona, it is a defense to a DUI prosecution if you pull off the roadway under circumstances which suggest you are removing yourself as a threat to the public by relinquishing control over the motor vehicle.  This defense is fact specific. If your case falls within this category, you must contact an experienced DUI practitioner and discuss this defense to your DUI charges.

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  • The INTERVENING DRINKING DEFENSE -- Drinking AFTER driving isn't drunk driving

  • You get home after a hard day, have several quick ones, and then the cops show up at the door.  They barge into your house or apartment and refuse to believe that you've consumed alcohol AFTER you were driving.  Then they arrest you for drunk driving.

  • You have a defense.  Several, in fact.

  • One is that the police entered your house illegally, without a warrant and without valid consent. 

  • But the other defense is the obvious defense.

  • You weren't drunk when you were driving.  You were drinking AFTER you were driving.

  • Intervening drinking is a valid defense to a drunk driving charge.  It can be the basis for challenging the arrest as illegal.  If the arrest is ruled illegal in court, then the case against the driver will fall apart.  (We have more on probable cause challenges to drunk driving cases at this page:  the PROBABLE CAUSE DEFENSES.)

  • If you were drinking after you were driving, this defense may apply in your case.  Don't assume it doesn't matter merely because the cops didn't pay any attention -- genus doesn't wear badges.  Be sure to save any alcohol containers from which you were drinking, bottles and glasses.  

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  • Most people think of "field sobriety tests" as a police tool to justify arresting someone for drunk driving.

  • But "FSTs" can turn into a mechanism for challenging blood test results -- one that can be very hard for the prosecution to handle.

  • If a driver's blood test results were high -- 0.20 for example -- then the driver's performance on field sobriety tests can contradict the accuracy of the blood test results.  A driver with a 0.20 alcohol concentration is at twice the highest "legal limit."  If that driver doesn't appear 'falling down drunk' in performing the field sobriety tests, then the test results are contradicted by the "field sobriety tests."

  • Field sobriety tests are designed to isolate persons who are only slightly over the "legal limit," not just those who are obviously drunk.  The standardized field sobriety tests developed by the National Highway Traffic Safety Administration were developed for the specific purpose of allowing police to distinguish those with alcohol levels of 0.10 from those below that level.  Moreover, it stands to reason that the higher the alcohol level, the progressively poorer one's performance should be on FSTs.

  • Faced with a defense which essentially pits two components of the prosecution's case -- the FSTs and the blood test results -- against each other, a prosecutor is stuck with having to argue that FSTs don't mean much.  But it is the prosecution which will have put the FSTs into evidence, and it will be obvious that police officers routinely rely on them.  In a case in which the defense need only establish a "reasonable doubt" of guilt to win, the "FIELD SOBRIETY TEST" DEFENSE can turn a prosecutor's own evidence against him.

  • This defense can also be used in conjunction with other defenses, to form a cohesive, multi-fronted strategy.  Where test results are challenged as inaccurate for other reasons, such as scientific challenges, poor machine maintenance,  or many other challenges, depending on the facts and circumstances of your case,  the FIELD SOBRIETY TEST DEFENSE can effectively reinforce these other defenses. 

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  • When a driver submits to a blood or breath test demanded by police under the Implied Consent Law, then the driver has a right to an "independent" test.  The driver's right to an "independent " test is a right to have a qualified person of his own choice administer a test, at the driver's expense.

  • So, under the Implied Consent Law, if you submitted to a blood or breath test at police request, then you were entitled to have a second test, administered by someone you chose, and pay for it yourself. 

  • Generally, when the police administer a blood test, they take a second tube of blood, secure it in evidence and thereafter it is available for defense retest.

  • Even though police officers are required to read the "Informing the Accused" form -- the form which spells out these rights of the driver and duties of the police -- to a driver before asking for a blood test or breath test under the Implied Consent Law, many police officers don't understand the legal requirements which that law places on them, and which are spelled out on the form.

  • Many times police officers ignore a request for an independent test. This is a defense. 

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  • The NO WARRANT DEFENSE -- Police can't come into your house without a warrant -- if they do, the violate the law and lose the case

  • Every year, police violate the Constitutional protection of the home to make drunk driving arrests.  Though a driver can't run from the police and hide in his home (that's the doctrine allowing warrantless entry in "hot pursuit" of a fleeing suspect), police have no legal right to enter a house merely because the occupant is someone they think was driving drunk.

  • A police officer who barges into a house without an occupant's consent and without a warrant is violating the Fourth Amendment, and any arrest made in the house is illegal and invalid.  Evidence obtained as a result of that arrest -- including test results, statements of the person arrested, and police testimony about their observations of that person -- will be "suppressed," which means it can't be used as prosecution evidence.

  • This rule, however, isn't restricted just to police entry into the home.  Even if police officers are legally admitted to the house -- for example, your spouse lets them in voluntarily  --  that doesn't mean they can go anywhere they want inside the house.  Police are subject to the same rules as any stranger or salesperson allowed into your home.  That is, they have to stay where they are put -- they can't roam around looking for their suspect or for evidence.  If they do, they violate the law as fully as if they'd entered illegally.

  • In the Welch case, the police entered without a warrant and then rousted the sleeping driver in his bedroom.

  • That was illegal then, and it's illegal now.  If police entered your house without a warrant to make an arrest, then this is a legal defense which you should be sure to have raised in your defense. 

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  • The INTERFERENCE WITH THE RIGHT TO COUNSEL Defense.

  • The police cannot deprive you of your right to consult with an attorney during a DUI investigation.  However, you do not have right to unreasonably delay the investigation in order to contact an attorney.  The ground between these two positions is where many a battle is fought in DUI defense. 

  • If you are under arrest, you must be advised of your right to remain silent.  Please note however, if the police do not read you your rights, your case is not dismissed.  The sanction is that anything you told the police after you were placed under arrest cannot be used as evidence. 

  • When are you considered under arrest?  Generally, when you are are handcuffed and not free to leave.  Legally, it is defined when your freedom of movement is restricted by the police where a reasonable person would believe they were not free to leave.  Do not confuse this with "investigative detention".  In Arizona, the police can detain your for further investigation.  How long this can be is generally settled on a case by case basis and is the subject of much litigation in a DUI defense.

  • Essentially, when the police are conducting field sobriety tests, this is investigative detention, you are not under legally under arrest, but you are not free to leave.  If you try to leave, the police of course will not let you, they will continue to detain you, and if you refuse the field test and/or refuse to cooperate in the investigation you will be place under arrest for DUI based on the subjective information they police have at that point.

  • An investigative detention cannot be any longer than is necessary for the police to accomplish their task.  This is always the exact amount of time the police need to establish probable cause to arrest you for DUI. 

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  • Defenses to drunk driving cases are best when they're custom tailored to your case.  If you don't think the defenses outlined on this page apply to your case, that doesn't mean there aren't defenses.  It means you need to have an talk with an attorney who focuses on drunk driving defense.  

  • The best defense to your drunk driving case may be one that hasn't been mentioned on this page -- because it is unique to the facts of your case.

  • We'd like to talk with you about your defenses.  Just give us a call at (888) 620-0001, toll free, or locally at 620-0000.

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