Common ways to fight a DUI or DWI charge

If you are charged with a DUI involving alcohol or drugs in Pennsylvania, you will face multiple penalties. You might face a suspension of your driving privileges, stiff fines, jail time, and other penalties. You should get help from an experienced DUI defense lawyer at DiCindio Law for help with defending against the charges against you. Depending on the facts and circumstances of your case, it may be possible to defend against the allegations and to win a dismissal of the charges against you. Your lawyer will analyze everything to decide whether you should fight your case through trial or should try to negotiate a plea to settle the charges against you. Some of the most common defenses to DUI charges in Pennsylvania are detailed below.

Lack of reasonable suspicion for your stop

In Pennsylvania, police officers must have a reasonable and articulable suspicion that a violation has been committed by a driver before they can stop them. Reasonable suspicion is not simply a hunch but instead must be based on objective facts. If an officer stopped you because he or she thought that you looked suspicious, but you had not committed any traffic offense, your West Chester DUI Attorney might be able to get the charges against you dismissed because of the unconstitutional stop.

Lack of probable cause for your arrest

After an officer stops you, he or she will investigate to determine whether there is probable cause to place you under arrest. Probable cause is more than reasonable suspicion but is less than the burden of proof that the prosecutor will have in proving your guilt at trial. The officer might try to build probable cause through his or her observations of your appearance, speech, and motor control. He or she might ask you to submit to standardized field sobriety tests and ask you to submit a preliminary breath test. All of these activities are geared toward building probable cause to support your arrest. If the officer did not have probable cause, your attorney may file a motion challenging the arrest and the admissibility of any chemical tests that were performed afterward. If your lawyer wins, the prosecutor will not be able to use the evidence against you. This could result in a plea offer to lesser charges or a dismissal of the case against you.

Improperly conducted roadblocks and checkpoints

The police are allowed to conduct DUI roadblocks and checkpoints. However, there are specific rules for how they may be conducted. Any checkpoint or roadblock must be announced in advance through the media and signs. It must be stationary, and the administration must decide to conduct the checkpoint rather than the police officers deciding to do it themselves. The decision about who to stop must be objectively based rather than based on an officer’s decision. For example, a roadblock might be used to stop every sixth car that passes through but not to stop someone that an officer simply wants to check out. Finally, the stop must be brief, and the officers are not allowed to search the vehicle. If you were stopped and arrested at a DUI checkpoint or roadblock, your lawyer will review how the DUI checkpoint was planned and conducted to see if it complied with the rules.

Problems with the breath test

Breath tests are the most frequently used type of chemical testing in DUI cases. However, breath tests may have several problems, including the following:

  • Tests conducted improperly
  • Gastric reflux within a 20-minute window
  • Instrument problems
  • Failing to observe the person before the test

If the machine is not calibrated correctly, the results may be inaccurate. Other problems can also happen. Your lawyer can request records from the police department to check its calibration and certification. He or she might also ask for information about the officer’s certifications and investigate any problems that occurred. If there were problems, your lawyer might challenge the breath test results to try to get them suppressed.

Residual alcohol in your mouth

A breathalyzer tests the contents of your breath from the deep lung tissue. However, you can have residual alcohol in your mouth that can distort the results. For example, if you suffer from acid reflux, have burped or vomited, or have alcohol-soaked particles trapped in your teeth, your breath test results can be falsely high.

Following a ketogenic or Atkins diet

Many people follow low-carb diets to try to lose weight. Diets such as Atkins or the ketogenic diet try to get people to enter a state called ketosis so that their bodies will burn fat. Ketosis causes your body to produce excess ketones, which can cause you to fail a blood-alcohol breath test even if you have not been drinking. When ketones are eliminated in your breath, they are converted to isopropyl alcohol. Breath tests cannot distinguish between ethyl alcohol and isopropyl alcohol. If you are on a ketogenic diet, tell your attorney.

Medical conditions

Certain medical conditions, including hypoglycemia and diabetes, can also cause your body to produce isopropyl alcohol similar to a ketogenic or Atkins diet. When fat stores in your body are burned for energy, ketones are produced and can cause falsely high BAC results on breath tests.

Problems with blood testing

Like breath tests, blood tests are not infallible. Several factors can taint your blood test results, including the following:

  • Improper storage of your sample
  • Blood contamination
  • Blood fermentation
  • Improper analysis
  • Technicians without the proper training or certification

Your attorney might request that your second vial of blood is submitted to a test to determine the accuracy of your test results. He or she might also look at records of how your blood sample was stored and request information about the chain of custody. Finally, he or she might look at how your blood was drawn and the certifications and training of the technician who performed the analysis. If there were problems, your blood test may be suppressed.

Problems with the field sobriety tests

While the standardized field sobriety tests are supposed to show indicators of impairment, they are not completely accurate. Only three of the tests have data to support them. Another problem is that the SFSTs must also be administered precisely and scored correctly. Many law enforcement officers make mistakes in administering the field sobriety tests. People also mess up on these tests because of such things as a lack of coordination, footwear problems, uneven surfaces, poor lighting, bad weather, and intimidation. Some people have medical conditions that cause nystagmus to naturally occur in their eyes. Your attorney might carefully review any video of your SFSTs and your medical records if you have a medical condition that affects your eyes.

Lack of impairment

In some cases, a person will show little or no impairment yet have a BAC that is high and should cause impairment. This type of case might indicate that something is wrong with your test, and the evidence should not be trusted. If there is a disconnect between your observed level of impairment and your BAC level, your attorney will investigate to figure out what went wrong with the test process.

You were not driving, operating a vehicle, or in actual physical control

To convict you of a DUI, the prosecutor will be required to prove that you were driving or operating a vehicle or that you were in actual physical control of it at the time of your stop. If an officer did not see you driving or found you sleeping in the backseat of your car when it is off without access to the keys, the prosecutor will have a difficult time proving that you were driving under the influence of alcohol.

Radio or electric interference

Electromagnetic and radio frequency interference can cause DUI chemical tests to provide falsely high BAC results. This is because electronic devices can interfere with the tests. While the prosecutor might argue that the breathalyzer machine has an RFI or EFI detector, the detectors on the machines are not reliable. This type of defense might be difficult to prove, but your attorney might consider it if a potential source of interference emits electromagnetic or radio waves in a specific frequency band that the detectors can’t detect.

Challenges based on the BAC error rate

Even if the police officer did not make mistakes when he or she administered your BAC test, the BAC tests that are used in Pennsylvania still have error rates. The error rates of Pennsylvania DUI tests range from 0.005% to 0.02%. If your BAC tested from 0.08% to 0.099%, your attorney might challenge the results based on the error rates. This is because your BAC might have been lower at the time than the minimum of 0.08% under 75 Pa.C.S. § 3802(b).

Misconduct by the police

If you were under the influence of alcohol or drugs, your charges might still be dismissed if the police officers engaged in misconduct. Police officers must follow proper procedures and must write accurate reports, comply with the rules that govern investigations, and testify truthfully. If the police officer ignores the procedures or fabricates evidence, the evidence that was unlawfully obtained or fabricated might be tossed out of court. If the misconduct was severe, the prosecutor might dismiss the charges against you.

Auto-brewery syndrome

A rare condition called auto-brewery syndrome has made the headlines across the U.S. in DUI cases. People might develop this condition as a side effect of diseases, including Crohn’s disease, short bowel syndrome, and diabetes. People who eat a diet that is high in carbohydrates and who also overuse antibiotics might develop this syndrome.

If you have auto-brewery syndrome, your gut can produce alcohol by fermenting carbohydrates that you have ingested. This is because of the presence of yeast in your small intestine. If you had a very high BAC and had not consumed any alcohol, your lawyer might ask for you to be tested for this condition. If you have it, your lawyer might get the court and the prosecutor to agree to dismiss your charges. Fortunately, this condition can be treated so that it will not cause further problems in the future.

Contact Our West Chester DUI Lawyers At DiCindio Law, LLC For More Help

If you are facing criminal charges and need legal help, contact the West Chester, PA DUI lawyers at DiCindioLaw, LLC to schedule a free initial consultation.

We serve in Chester County and its surrounding areas:

DiCindio Law, LLC
29 S Walnut St
West Chester, PA 19382
Open 24 hours
(610) 430-3535


***This blog article is made available by the law firm publisher for educational purposes and to provide general information, not to provide specific legal advice. By reading, you understand that there is no attorney-client relationship between you and the publisher. The above-listed information does not include the entire criminal code, annotations, amendments, or any recent changes that may be relevant. The information provided is for informational purposes only and may not reflect the most current legal developments. These materials are not intended, and should not be taken, as legal advice on any particular set of facts or circumstances. Please contact DiCindio Law, LLC for a consultation and to discuss what law is relevant to your case.***