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Police Evidence at The APS Hearing – DUI Checkpoint Defense

dmv defense aps police hearing


What is Probable Cause?


Probable Cause is the standard by which an officer or agent of the law has the grounds to contact a citizen, make a traffic stop, make an arrest, conduct a search or obtain warrants. The term comes from the Fourth Amendment to the United States Constitution:

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.


The Oxford Companion to American Law defines probable cause as “information sufficient to warrant a prudent and cautious person to believe that an individual has committed a crime or that sufficient evidence exists to warrant further investigation.”


What is Evidence of Impaired Driving?

In DUI arrests, probable cause usually centers on the circumstances which causes a police officer to make initial contact with a driver, which then results in the driver’s arrest for DUI. In most DUI cases, an arrest occurs after a police officer witnesses some violation of the California Vehicle Code and conducts an enforcement stop to cite or warn the driver. An officer may witness violations such as speeding, failing to stop for a red light, or a stop sign violation. These issues are not necessarily evidence of impaired driving but certainly are probable cause for a police officer to affect an enforcement stop. Failing to turn on a vehicle’s headlights at night or having mechanical problems with a car also provides a police officer a reason to make a traffic stop.

In their overzealous focus to remove drunk drivers from the road, police officers will often resort to stopping motorists at will and then “invent” their probable cause later. This classically occurs during the early morning hours when the percentage of impaired drivers is thought to be higher. Police officers will “troll” through areas where restaurants and bars are located and will stop drivers simply because they leave a location where alcohol is served. In the law enforcement community, this is referred to as “cherry picking.” The driver may not have committed a single violation of the law; the driver may not have demonstrated a single “clue” that he/she is impaired but they are stopped nonetheless. The officer makes his initial contact with the driver and, if the driver is determined to be sober, the officer may simply say he stopped the driver because his car met the description of one the officer was searching for. On the other hand, if the driver is thought to be impaired, the officer will “invent” his probable cause for the stop by alleging that the driver had been “weaving.” This is a completely subjective evaluation of a person’s driving pattern but is prolific in police reports.

The California Vehicle Code also empowers police officers to conduct enforcement stops on vehicles for a wide range of violations that are not necessarily thought to establish the symptoms of impaired driving but, nonetheless, can lead to a DUI arrest:Faulty or non-functioning lighting equipment,Obstructed Windshield (necklace hanging from rear-view mirror),Cracked Windshield,Loud Radio,Tinted Windows,Expired Vehicle Registration,Vehicles equipped with Substandard Mudflaps,Bald Tires and Loud Exhaust.


  • Speeding
  • Driving too Slowly
  • Weaving
  • Failure to Properly Stop for Stop Signs
  • Failure to Stop at Traffic Lights
  • Pausing Too Long at a Stop
  • Driving at Night without Headlights
  • Illegal U-Turn
  • Failure to Use Turn Signal


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Clearly a creative police officer who is intent on making DUI arrests is armed with a vast array of reasons to stop a motorist and, when he can’t find something listed above, he will simply say the driver was “weaving.”


 Attacking the Probable Cause for a traffic stop is certainly a core element to defending drivers at a DMV Administrative Hearing. A complete investigation of the events leading up to the stop or initial contact with the client is crucial. Because police officers are specifically trained to establish probable cause and because they are trained in the methods to properly document their actions in a police report, probable cause attacks can be difficult. Review of independent witnesses, dash-cam video, or other sources of video may give the driver’s representative just the ammunition necessary to defeat the initial stop or contact. If the Probable Cause for the stop if faulty, this is cause to win a hearing.

Sobriety Check Points – The Facts

Another mechanism used by police officers to draw drivers into DUI arrests is the check-point. Today’s sobriety check point has its roots in the Road Blocks and Check Points that originated in the 1970’s. In that era, police agencies set up “check points” as a means to conduct safety inspections and to determine if drivers were properly licensed. During the course of these “inspections” police made numerous DUI arrests and the idea of the sobriety check-point was born.

In defending a client at a DMV administrative hearing, the driver’s representative should carefully review and investigate the check-point as there are many instances where police agencies violate the necessary safe-guards established by the Supreme Court. If the check-point is set up in violation of these specific guidelines, the original Probable Cause for stop may be faulty. This would be cause for a driver to win his or her hearing.

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Learn the details about the field sobriety test.

Imagine standing on the side of a busy interstate freeway with automobiles and semi-trucks screaming past you at high-speed. You are face to face with a uniformed officer who is loud, aggressive and demanding that you submit to a series of balance type tests that would be difficult for a gymnast to perform. The traffic going by is so loud that you can’t hear the officer speaking and when you ask him to repeat himself, he gets angry.

You’ve just come from a dance club and you’re wearing a dress that keeps blowing up and you’re wearing 4″ heels. It’s 50 degrees outside and you’re shivering, but the officer is comfortable in his heavy jacket and gloves.

Maybe you’re overweight or elderly. Maybe you have had reconstructive surgery on your knees or have a fused spine.

You’re staring directly into the bright headlights and spotlights of the patrol car and the officer’s partner is now searching the interior of your car. You’ve never been in this type of trouble before and you are terrified.

Welcome to the world of the DUI investigation. The goal of the Field Sobriety Test (FST) is for a police officer (usually not trained in physiology) to put a driver through a series of psycho-motor tests to determine that person’s ability to safely operate a motor vehicle. Field Sobriety Tests are completely subjective and allow a police officer to interpret a driver’s performance in any fashion that he/she determines appropriate. The officer has the complete power to disregard or ignore pre-existing medical conditions, environmental factors, distractions or fear. Essentially, the officer can see what he wants to see.

Many drivers believe they are “required” to submit to Field Sobriety Tests at the request of a police officer. In fact, FST are not legally required. The only thing a driver is required to do, prior to arrest, is to properly identify himself/herself and to not be physically resistant to an officer. A driver is not required to answer probative questions about where they have been, where they are going, or what they have eaten. Drivers are not required to answer questions regarding the use of alcohol or if they are feeling the effects of alcohol. Despite this, most drivers feel the obligation to be cooperative with the police and they answer every question posed and perform every test requested. Trust me, in this situation; the officer is not there to be your friend. He is there to make an arrest.

The officer’s observations and evaluation of a driver’s performance of FST is a critical element of the DMV’s case. The DMV Hearing Officer will routinely admit the officer’s observations of Field Sobriety Tests as evidence of impairment and therefore rule that the arrest of the accused driver was legal. Representatives of drivers at administrative hearings must be prepared to attack the quality and accuracy of the police officer’s field investigation as a means to prove the arrest was not warranted.

Below is a list of the most common Field Sobriety Tests being administered by police officers in California:

Horizontal Gaze Nystagmus (HGN)
This is a test where the officer will pass a pen light, pen or finger in front of the driver’s face from left to right on a horizontal plane. As the driver tracks the moving stylus with his eyes, the officer is looking for the tell-tale sign of impairment. A horizontal bouncing or twitching of the eyes is “Nystagmus.” Classically, a person who has been drinking will display a varying degree of bouncing in the eyes. This is an involuntary reaction that the driver does not feel. One’s eyes could be bouncing like ping pong balls and they would not feel a thing. The theory is, the more pronounced the nystagmus is or, the sooner the eye begins to bounce, the more intoxicated the driver may be. This is one way to determine if a person has been drinking, however, there are a multitude of other factors which can create this condition. Previous head injuries, the wearing of contact lenses, high doses of caffeine and certain medications can cause the eyes to react in this fashion; and, a certain percentage of the population have naturally occurring nystagmus.

One Leg Stand
The officer will instruct the driver to stand with his/her feet firmly on the ground with heels and toes touching. When instructed to begin, the driver is to raise one foot approximately 6 inches off the round and point their toe. With their hands held closely at their sides, the driver is to look at the elevated foot and then count from 1 to 30. The officer will tell the driver that if they drop their foot, they should simply recover and continue counting.

The officer does not tell the driver that if they drop their foot one time, it is considered a failure. They do not tell the driver that using their arms for balance, hopping to maintain balance of failing to count are also considered failures of the test.

Walk and Turn
Classically referred to as the “heel to toe,” this test begins with the officer placing the driver in the “position of instruction.” The officer tells the driver to place one foot directly in front of the other with the heel touching the toe. The driver is instructed to remain still, in this position, while the officer completes the remainder of the instructions. The officer will tell the driver, “when I tell you to begin,” to take nine steps in a straight line, touching the heel to the toe on each step. The driver is told to keep his arms at his side and to count each step as he walks. The driver is then told to pivot 180 degrees and take an additional nine steps in the opposite direction.

The officer does not tell the driver that if he/she begins the test before being instructed to do so, it is a failure. Not touching the heel to the toe on each step is a failure. Stepping out of line is a failure. Raising the arms for balance is a failure. Failing to count the steps out loud is a failure and, failing to perform the pivot as instructed is reason for failure. Taking too few or too many steps is a failure.

Modified Position of Attention (MPOA)
Sometimes referred to as the “Romberg” this test begins with the officer placing the driver into the position of instruction. The driver is directed to stand with his feet firmly on the ground with heels and toes touching. The driver is instructed, “When I tell you to begin” to tilt his head back, close his eyes and then to silently estimate the passage of 30 seconds in his/her head. The driver is told to keep his/her arms to their side and, when they believe 30 seconds has elapsed, to tilt their head forward, open their eyes and say “now.”

The officer does not tell the driver that incorrectly estimating the passage of time is a failure.
Beginning the test before being instructed is also a failure. Opening the eyes or raising one’s arms for balance is a failure. And the officer will move around the driver to monitor whether or not the driver is “swaying” while tilting his head.

Finger to Nose
This test begins with the driver being placed into the position of instruction. The driver is instructed to stand with his/her feet firmly on the ground with the heels and toes touching. The officer instructs the driver to keep his/her arms at their side with the index finger on each hand pointed toward the ground. The driver is told, “When I tell you to begin,” to tilt their head back and close their eyes. The driver is told that he/she will be instructed to use their right or left hands, as instructed, to reach up and touch the very tip of their extended index finger to the very tip of the nose. The driver is told that as soon as they touch the instructed finger to the nose that they should immediately drop their hand back down to their side and await the next instruction.

The officer does not tell the driver that beginning the test before being instructed, is a failure. That touching any portion of the extended finger, other than the very tip, to any portion of the face, other than the tip of the nose, is a failure. Raising the wrong hand when instructed is a failure. Not dropping the hand automatically after touching the nose is a failure. Swaying while standing with the head tilted back is a failure.

Finger and Thumb
This test begins with the driver being instructed to raise either hand and touch the tip of the thumb to the tip of the pinky finger. The driver is told, “When I tell you to begin,” to alternatively touch the tip of the thumb to the tip of each finger, while counting, “one, two, three, four;” and to then automatically reverse the order while counting, “four, three, two one.” This completes one cycle. The officer will normally tell the driver to complete three cycles while counting out loud.

The officer does not tell the driver that failing to touch the tip of each finger in sequence is a failure. The officer does not tell the driver that breaking the sequence or not counting correctly is a failure. Not completing exactly three cycles is a failure.

Hand Pat
This test begins with the officer telling the driver to place the palms of both hands together in a clapping posture. The driver is told, “When I tell you to begin,” rotate the top hand 180 degrees and clap with the other hand. The effect is that the driver claps his right hand into the palm of his left hand. The right hand is then completely rotated and brought down to clap the left hand with the back of the right hand. As the driver is performing, the officer will begin barking for the driver to perform “faster, faster, faster.”

The officer does not tell the driver that “rolling” the hand rather than completely “rotating” the hand is a failure. Striking the left hand with the knife edge of the right hand is a failure. Not rotating the hand at all is a failure.

Recite the Alphabet
The driver is told to recite the alphabet meticulously and to not do it in a “singing” manner. This author has actually witnessed police officers instructing drivers to perform the alphabet in reverse order, which is utterly preposterous.

This author has witnessed police officers hand the driver a 3×5 card and instruct the driver to print the alphabet on the card and then to sign their name below the letters.

Counting Backwards
In this test, the officer will pick two random numbers and instruct the driver to count backwards from one number to the other. In example, the officer may tell the driver to count backwards from 97 to 73.

What is the Field Breathalyzer?

The vast majority of California Police Agencies now equip their patrol officers with small hand-held breath testing devices commonly referred to as “PAS” or “EPAS” devices. PAS is the acronym for the Preliminary Alcohol Screening device. EPAS denotes the supposedly more sophisticated Evidentiary Preliminary Alcohol Screening device. Both of these devices are small, portable, hand-held breath devices that are plastic in construction and often grey, black or yellow in color.

The earliest versions of these devices were simple tubes or balloons that would turn a particular color to indicate the mere presence of Ethanol (ETOH) on the driver’s breath. These early versions made no attempt to estimate the actual alcohol level and therefore were used simply as a means for the officer to confirm the driver had, in fact, been drinking alcohol.

Over the past several decades, PAS and EPAS devices have developed to the point that police officers now primarily rely upon the breath device in making the decision to arrest or release a driver. Police Officers will routinely arrest a driver who has blown .08% or higher on a PAS or EPAS device, even though the driver may have performed all the other Field Sobriety Tests with flawless accuracy. In this instance, the officer makes an arrest based upon the presumed accuracy of a breath machine even though every “physical” evaluation of the driver indicates that he/she is not impaired.

At the DMV Administrative Hearing, the DMV Hearing Officer will determine that a driver’s license suspension is warranted if the PAS or EPAS device indicated an alcohol level at or above .08%, even if the driver performed all other Field Sobriety Tests correctly.

California Law explicitly allows a driver to decline any breath testing at the side of the road, prior to being arrested. There are a few exceptions to the rule:

  1. Any driver, under the age of 21, must submit to a PAS or EPAS test at the request of police officer.
  2. Any driver, who is currently on probation for DUI, must submit to a PAS or EPAS test at the request of a police officer.
  3. Any driver, who is currently on probation for any criminal violation; where a specific condition of probation is blowing into a PAS or EPAS device, must submit to a test at the request of a police officer.
  4. If a driver is under arrest and there is no other chemical test (blood or breath) reasonably available, the driver must submit to a PAS or EPAS test.
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