Last Updated on February 9, 2025 by Keith E. McAndrews, Esquire
DUI cases are notoriously difficult to win in court. However, there are a few telltale signs that a DUI case is weak and may be worth fighting. Therefore, if you are facing a DUI charge, it is essential to have an experienced driving while intoxicated lawyer fighting for you in court. In the following blog post, I will go over some common and uncommon reasons the district attorney may have difficulty convicting you of driving under the influence.
Key Takeaways
You may have a weak DUI case that could be dismissed in court if any of the following situations apply:
- The police pulled you over for a pretextual reason unrelated to a DUI
- The police are unable to prove you were the driver of the car while DUI
- You were impaired but legally justified in driving the vehicle
- The police did not perform field sobriety testing
- The police conducted field sobriety tests, and you had a physical disability or medical condition that affected the accuracy of the tests
- The police lost, misplaced, or destroyed dash cam or body cam evidence
- Your blood alcohol content was inside the margin of error
Bucks County DUI Lawyer
Have the police charged you with a weak or questionable DUI in Bucks County, Montgomery County, Delaware County, Philadelphia County, or Chester County, Pennsylvania?
Fortunately, I have over a decade of experience defending drivers in Philadelphia and suburban Pennsylvania Counties. In addition, I offer:
- Affordable, transparent rates
- Payment plans
- One-on-one communication with all clients throughout the case
- A will to win every case
Contact me at (215) 752-5282 twenty-four hours a day, seven days a week, for a free driving under the influence consultation. I will review the facts of your case and any available DUI defense strategies. You can also reach me through my confidential contact form for an immediate response.
The Police Conducted a Pretextual DUI Car Stop
In a pretextual vehicle stop, the police pull you over for suspicion of drugs or weapons possession but claim that the basis for the stop is due to suspicion of the driver’s license suspension or some other minor traffic violation. Commonly, it is drug interdiction masquerading as a DUI or traffic violation pullover.
The United States Supreme Court Ruling Regarding Pretextual Car Stops
It is crucial to understand that pretextual car stops are illegal under Pennsylvania law and the 2015 United States Supreme Court case of Rodriguez v. United States. This ruling serves as a shield, protecting your Fourth Amendment rights against illegal searches and seizures during routine traffic encounters with the police.
What the Rodriguez Case Means
The Rodriguez case sets a clear boundary for police conduct during minor traffic stops. The Supreme Court ruling holds that when the police pull a citizen over for a traffic violation, they must adhere to “the mission of the traffic stop.”
The mission of the traffic stop was defined as checking for:
- Driver’s license
- Vehicle registration
- Car insurance
- Active warrants
In Rodriguez, the Court ruled that the police must have immediate reasonable suspicion or probable cause of a crime before questioning a driver about unrelated criminal activity (going outside the mission of the traffic stop).
In most cases I have handled, the police cannot establish reasonable suspicion or probable cause for an unrelated crime when they question drivers about drugs, weapons, or other criminal activity during a traffic stop. It is usually an illegal fishing expedition.
Successfully challenging false pretense DUI car stops in court is a viable option. If the judge determines that the police stopped you under illegal pretenses, the evidence seized from the unlawful search and seizure will be suppressed.
Once the court suppresses the evidence, the prosecutor may withdraw your case. Suppose that does not occur. In that case, the judge will rule that you are not guilty of the DUI.
How Can I Tell if My DUI Vehicle Stop Falls Under the Rodriguez Case?
There are six main components of an illegal Rodriguez police stop:
- The police pull you over for a minor traffic violation
- When the police approach the driver’s side of your vehicle, they will almost immediately begin interrogating you about the presence of drugs, weapons, or other contraband in the car unrelated to the original traffic stop (You are now subject to an unconstitutional seizure under the 4th Amendment).
- The police lacked reasonable suspicion or probable cause when they began questioning you about unrelated criminal acts
- Through coercion or consent given under duress, the police search your vehicle and uncover drugs, weapons, alcohol, or drug paraphernalia
- If drugs or alcohol are found, it is almost guaranteed that the police will charge you with DUI in addition to charges for any illegal items found in the car
- If you admit to drug or alcohol use, even if the police search uncovers nothing, the police will file DUI charges against you
Were you the subject of an illegal car stop that resulted in a DUI? Contact me at (215) 752-5282 for a free review of your case.
The Police Can’t Prove You Were Driving the Car
Being behind the wheel of a car does not automatically mean that the police can prove the “actual physical control” element to convict you of DUI. In other words, the police can’t prove you were driving the car while DUI.
Furthermore, there are many completely innocent situations where a person may be behind the wheel of a vehicle but not driving while impaired by drugs or alcohol, including:
- Instead of driving, you choose to sleep in your car until you are sober
- You are not drunk but are too tired or fatigued to drive safely
- You switched places with the actual driver of the car and the car is parked
- You are behind the wheel of a vehicle parked in a convenience store and the engine is off
If the police can’t prove you were driving the vehicle, and not just sitting in the driver’s seat, it is unlikely that the district attorney will be able to prove you are guilty of DUI.
You Were Legally Justified to Drive Under the Influence
Most people believe that the justification defense only applies in assault cases (self-defense). However, the justification defense also applies in DUI and driving under suspension cases.
The Bucks County Justification DUI Case
Fleeing a Violent Threat
For example, I won the dismissal of DUI charges in a case where my client was charged with driving under the influence of marijuana in Bucks County, Pennsylvania. The client was followed continuously in her car by a stalker from New Jersey into Bucks County, where she ultimately ran out of gas.
The stalker proceeded to damage the client’s vehicle and fled the scene. The client called the police to report the stalking incident and was arrested for DUI. The client requested a jury trial, and I argued that she was justified in driving under the influence due to the severe threat she faced from the stalker.
Fortunately, I persuaded the district attorney to withdraw all DUI charges halfway through the pre-trial suppression hearing. As a result, the DUI judge granted the withdrawal of the charges.
DUI Justification Legal Standard
The PA DUI justification law requires that the harm you are attempting to avoid be greater than the harm caused by driving under the influence. Therefore, fleeing a violent physical threat by another person would satisfy the legal standard for the DUI justification law, as a violent assault would be more significant than the harm caused by driving while impaired.
The main takeaway of the DUI justification defense is that you are entitled to drive impaired to avoid an immediate threat to your physical safety. However, you must immediately pull over and cease driving once the danger subsides.
Driving Impaired or Suspended Due to A Medical Emergency
Suppose the driver of your vehicle suffers a medical emergency? Under those circumstances, you would be legally justified to take control of the car to drive to a hospital to seek immediate medical treatment even if your license is suspended or if you are technically over the DUI blood level legal limit.
Contact me at (215) 752-5282 to discuss under what situations the law permits you to drive impaired or with a suspended license.
The Police Failed to Perform Field Sobriety Tests
If the police fail to conduct DUI field sobriety tests before a DUI arrest, the entire case can be dealt a death blow. There are many reasons that the police may decline to ask you to submit to field sobriety testing, including:
- You were seriously injured as a result of a traffic accident
- You were in a medical state of shock as a result of head trauma
- You have a pre-existing physical injury that prevented you from attempting to perform any of the tests
- There is no safe place for you to take the tests (ex., a high-traffic area without a roadway shoulder)
- The weather conditions did not permit field sobriety testing (heavy rain, high winds, sub-freezing temperatures)
The absence of field sobriety tests in a DUI case can make it almost impossible for a prosecutor to prove that you were driving while impaired. Also, prosecutors always want evidence that a driver failed field sobriety testing to present to a judge or a jury.
Moreover, the absence of field sobriety testing gives the accused the right to challenge the legality of the DUI arrest in a pre-trial hearing referred to as a suppression hearing. This lack of evidence gives you the right to challenge whether the police had probable cause to arrest you for DWI.
If the judge concludes that the police officer’s failure to conduct the tests made the stop illegal, the court will dismiss the case.
I have a track record of getting DUI charges dismissed when law enforcement officers do not conduct standardized (scientifically validated) or non-standardized (not scientifically proven, vary with each police department) field sobriety tests.
The Police Performed Field Sobriety Tests, and You Had a Physical Injury, Disability, or Medical Condition
During a DUI investigation, the police may ask you to perform different standardized and non-standardized DUI field sobriety tests, including:
- Walk and Turn
- Heel Toe Test
- Finger Nose Test
- DUI Pen Test
- Modified Romberg Balance Test
- Alphabet Test
Physical Disabilities and Medical Conditions Can Affect the Accuracy of Field Sobriety Testing
DUI field sobriety tests are difficult to perform for completely healthy people to perform who have no drugs or alcohol in their system.
Unfortunately, absent a serious life-threatening injury requiring immediate medical attention, the police will almost always request that you complete physical field sobriety tests even when you have a bodily injury, physical disability or medical condition that would interfere with your ability to complete the tests.
Always declare a physical injury or disability to the police before attempting to complete field sobriety tests. Otherwise, the police will claim you never mentioned any physical limitations and your truthfulness can be questioned in court.
Common Medical Conditions and Physical Disabilities that Affect the Reliability of FSTs
- Arthritis in any part of the body (restricted physical movement)
- A chronic back condition (lack of balance, coordination, physical movement)
- Diabetes (dizziness, shakiness, lack of concentration)
- Asthma (shortness of breath, inability to complete physical tasks)
- Anxiety, ADHD, PTSD (can trigger panic attacks, inability to concentrate and follow instructions)
- A joint replacement (limitations on physical movement)
- Extreme fatigue (confusion, inability to concentrate)
- Heart conditions (fatigue, lack of coordination and balance)
- Prescription medication side effects (inability to concentrate)
Existing physical injuries, disabilities and medical conditions adversely affect your coordination, ability to walk, stand, balance, and follow instructions.
When you attempt to complete DUI field tests with any of these physical injuries or medical conditions, you will not pass the test if the test requires a pass-fail. If it is not a pass-fail test, the police will claim you are demonstrating a DUI clue and consider that as evidence of impairment.
Why the Police Are Unable to Factor Injuries or Medical Conditions into Field Sobriety Testing
None of the law enforcement DUI investigation training programs, including the Pennsylvania State Police DUI Training, Advanced Roadside Impaired Driving Enforcement (ARIDE), or Drug Recognition Expert (DRE), provide instructions on how the police are to factor in or weigh the results of field sobriety testing when the testing is conducted on a person with a physical disability or medical condition.
As a consequence, the results of field sobriety tests conducted on drivers with physical limitations or medical conditions affecting their performance are presumptively unreliable and should be excluded as evidence in court.
How to Challenge Field Sobriety Test Evidence in Court
A pre-trial Motion to Suppress Evidence can be filed in the Court of Common Pleas to preclude the field-testing evidence from being used against you in court.
Under these circumstances, a judge is more likely to exclude field sobriety test evidence from being used by the prosecutor as evidence in your case. As a result, you will have knocked out a large part the prosecutor’s case, leaving you in a stronger position to get the case thrown out or plea bargained for a lesser charge.
The Police Lost or Destroyed the Dash Cam or Body Cam Evidence
DUI body cam and DUI dash cam recordings are crucial evidence in a driving under the influence case. In many cases, dash cam and body cam evidence will directly contradict the police officer’s written descriptions of the Defendant’s driving behavior.
In addition, the video and audio evidence can provide you with a basis to challenge the police officer’s description of the accused’s appearance, their performance on field sobriety tests, and other issues in the case.
DUI Judges and Juries are Suspicious When the Police Destroy Evidence
A judge or jury will view the unexplained loss or destruction of body cam and dash cam evidence with suspicion. Furthermore, the law permits a judge or jury to conclude that the missing evidence would have been favorable to the accused.
I have participated in many trials where the police did not produce evidence in their possession. In most cases, the jury acquitted my clients of all charges if the police lost, misplaced, or destroyed evidence.
Your Blood Alcohol Level is Within the Margin of Error
What is the Margin of Error for DUI Blood Alcohol Content?
The margin of error or variance in DUI breath and blood test results refers to the range within which the blood alcohol reading may vary from the actual or “true” blood alcohol content. The margin of error will have an upper and lower limit.
In other words, the margin of error is the extent of possible inaccuracy in a DUI blood or breath test due to human mistakes, failure to follow lab protocols, lab conditions, or other factors that could cause the BAC result to be inaccurate.
The margin of error for many breathalyzer devices is .01 percentage points. Suppose your BAC is .08%? The .01% margin of error means that your actual blood alcohol reading could be as low as .07%, which is below the legal limit for driving for an adult in Pennsylvania.
As a result, your blood alcohol content would be under the legal limit, and the prosecutor would withdraw the case, or a judge would issue a not-guilty verdict.
The Impact of Margin of Error on BAC Readings Above the Legal Limit
Suppose your blood alcohol test falls within the margin of error for readings near 0.10% or 0.160%. In that situation, your DUI charge will be reduced to the next lowest tier, significantly reducing jail time, court costs, and the mandatory DUI fine.
For example, A DUI BAC result falling within the margin of error for a DUI BAC charged as 0.01% would mean the difference between facing a mandatory 48 hours in jail and a 12-month license suspension and serving no jail time and no license suspension (first-tier DUI).
You should review the margin of error in DUI cases where the blood alcohol amount is slightly above the legal limit with a BAC reading near:
- 0.08%
- 0.10%
- 0.16%
Specific DUI blood alcohol levels are on the Pennsylvania DUI Penalties page.
How Do I Determine the Margin of Error in My DUI Blood or Breath Test?
There are generally two ways to figure out what the margin of error is for the DUI blood alcohol reading. The BAC margin of error is usually listed in the toxicology report submitted as evidence by the prosecutor in your case.
Most police departments in suburban Philadelphia Counties use a private laboratory service to conduct DUI blood testing.
What if the margin of error is not listed on the lab report? In that case, you can hire a private defense toxicologist or pharmacologist to determine the margin of error by reviewing the state’s laboratory report. I have gotten many DUI charges thrown out using this method.
Finally, it is critical to know that the margin of error is higher in DUI breath test results than in DUI blood test readings. To learn about other driving under the influence defenses, visit PA DUI Defenses.
Bucks County DUI Attorney
Have the police charged you with DUI involving any of the circumstances described in this blog post? If so, I may be able to get the police or prosecuting attorney to drop or reduce the charges.
I defend drivers in Philadelphia County, Bucks County, Montgomery County, Delaware County, Chester County, Northampton County, and the nearby Pennsylvania Counties.
I am available for DUI consultations during business hours, after hours, and weekends. Contact me at (215) 752-5282 or complete the confidential contact form for a quick response.