How to Challenge Breathalyzer Results in York County DUI Cases

Being arrested for DUI in York County is a stressful experience, especially when your charges are based primarily on breathalyzer results showing a blood alcohol concentration (BAC) above Pennsylvania's legal limit. However, breathalyzer tests are not infallible. These sophisticated machines can produce inaccurate readings due to calibration errors, improper administration, medical conditions, or environmental factors.

If you're facing DUI charges in York County based on breathalyzer evidence, understanding how to challenge these results can make the difference between a conviction and dismissed charges. This comprehensive guide explains the science behind breathalyzer tests, common sources of error, and proven defense strategies specific to York County DUI cases.

Understanding Breathalyzer Technology

Breathalyzer devices used in Pennsylvania measure the amount of alcohol in your breath and convert it to estimate your blood alcohol concentration. York County law enforcement primarily uses two types of breath testing devices:

Preliminary Breath Tests (PBTs): These portable roadside devices give officers probable cause for arrest but are not admissible as evidence of your actual BAC in court.

Evidential Breath Testing Devices: These larger, more sophisticated machines are typically located at police stations. In Pennsylvania, the most commonly used evidential devices are the Intoxilyzer and DataMaster models. These results ARE admissible in court and often form the prosecution's primary evidence.

Breathalyzer devices use infrared spectroscopy or fuel cell technology to detect alcohol molecules in your breath sample. The machine assumes a standard partition ratio (the relationship between alcohol in your breath versus your blood) of 2100:1. This means the device assumes that the concentration of alcohol in 2,100 milliliters of alveolar breath equals the concentration in 1 milliliter of blood.

However, this partition ratio varies significantly between individuals based on body temperature, breathing patterns, metabolism, and other physiological factors. This fundamental assumption creates one avenue for challenging breathalyzer accuracy.

Common Sources of Breathalyzer Error

Breathalyzer results can be challenged on numerous grounds:

Calibration and Maintenance Issues

Pennsylvania law requires that evidential breath testing devices be inspected, calibrated, and certified regularly to ensure accuracy. The Pennsylvania Department of Health maintains strict protocols for calibration schedules.

If the breathalyzer device used in your York County arrest was not properly calibrated within the required timeframe, the results may be inadmissible. Defense attorneys can subpoena maintenance and calibration records to identify gaps in compliance.

Operator Error and Training Deficiencies

Breathalyzer tests must be administered by certified operators who have completed specific training programs. Pennsylvania requires a 20-minute observation period before administering an evidential breath test to ensure you haven't consumed anything, regurgitated, or placed anything in your mouth that could affect results.

Common operator errors include:

• Failing to observe you for the full 20 minutes

• Not checking your mouth for foreign objects

• Providing inadequate instructions on how to blow into the device

• Failing to recognize error messages or improper readings

• Not documenting environmental conditions that might affect results

If the officer who administered your test in York County lacked proper certification or deviated from required protocols, the results can be challenged.

Medical Conditions That Affect Accuracy

Several medical conditions can cause breathalyzers to register falsely high BAC readings:

Gastroesophageal Reflux Disease (GERD): This condition causes stomach acid and contents to flow back into the esophagus and mouth, potentially bringing alcohol from your stomach into your mouth, which dramatically inflates breath test results.

Diabetes and Ketosis: Individuals with diabetes or those on ketogenic diets may produce acetone and other ketones that breathalyzers can mistake for ethyl alcohol, resulting in falsely elevated readings.

Breath Temperature Variations: Every degree Celsius that your breath temperature rises above the assumed standard increases the apparent BAC by approximately 6-7%. Fever, physical exertion, or even environmental heat can elevate breath temperature.

Dental Work and Mouth Alcohol: Dental bridges, caps, or dentures can trap alcohol in your mouth. Recent use of mouthwash, breath spray, or cough medicine containing alcohol can also create mouth alcohol contamination.

Rising BAC Defense

Alcohol takes time to be absorbed into your bloodstream. Your BAC continues rising for 30 minutes to two hours after your last drink, depending on numerous factors including what you ate, your body composition, and the type of alcohol consumed.

If you were stopped and tested shortly after finishing your last drink, your BAC at the time of the test might be higher than it was when you were actually driving. Since Pennsylvania law makes it illegal to drive with a BAC of 0.08% or higher, your BAC at the time of driving is what matters—not your BAC 30, 60, or 90 minutes later at the police station.

This rising BAC defense requires expert testimony to demonstrate that your BAC was below the legal limit while you were operating your vehicle, even though it tested above 0.08% later.

York County-Specific Considerations

York County DUI cases are processed through the York County Court of Common Pleas. Understanding the local procedures and standards can strengthen your defense:

Breathalyzer Locations: Most evidential breath tests in York County are administered at police stations in York City, West Manchester Township, Spring Garden Township, and other municipal departments throughout the county. Each location should maintain its own calibration and maintenance records.

Local Law Enforcement Practices: Different York County police departments may have varying levels of training and compliance with breathalyzer protocols. Some departments have documented histories of calibration lapses or operator errors that can be relevant to your defense.

York County Prosecutors: The York County District Attorney's Office prosecutes DUI cases aggressively but is also receptive to legitimate scientific challenges to breathalyzer evidence when properly presented.

Building Your Defense Strategy

Successfully challenging breathalyzer results requires a multi-faceted approach:

1. Immediate Evidence Preservation

Request all documentation related to your breathalyzer test immediately, including:

• Calibration and maintenance records for the specific device

• Operator certification and training records

• Video footage of your arrest and testing

• Police reports and booking documents

• Your own medical records if relevant conditions exist

2. Expert Witness Testimony

Breathalyzer challenges often require testimony from forensic toxicologists or other scientific experts who can explain technical flaws to a judge or jury. These experts can:

• Analyze calibration records for deficiencies

• Explain how medical conditions affected your results

• Calculate your actual BAC at the time of driving using retrograde extrapolation

• Identify operator errors or protocol violations

3. Suppression Motions

Your attorney may file pretrial motions to suppress breathalyzer evidence if:

• The traffic stop lacked reasonable suspicion or probable cause

• The breathalyzer device wasn't properly calibrated

• The operator wasn't properly certified

• Required observation periods or protocols weren't followed

4. Alternative Explanations

Presenting alternative explanations for elevated BAC readings—such as GERD, diabetes, mouth alcohol, or rising BAC—can create reasonable doubt about the accuracy of the prosecution's primary evidence.

The Importance of Independent Blood Testing

Pennsylvania law gives you the right to obtain an independent blood test after a breathalyzer test. If you requested independent testing and were denied, this can be grounds for challenging the breathalyzer results.

If you did obtain independent blood testing and it shows a lower BAC than the breathalyzer, this discrepancy can be powerful evidence that the breath test was inaccurate.

What About Refusing the Breathalyzer?

Some drivers choose to refuse breathalyzer testing. While this eliminates breathalyzer evidence against you, Pennsylvania's implied consent law imposes automatic penalties for refusal, including a 12-month license suspension for a first refusal.

Refusing the test also doesn't prevent prosecution—the Commonwealth can still pursue DUI charges based on officer observations, field sobriety test performance, and other evidence.

The Path Forward

If you're facing DUI charges in York County based on breathalyzer evidence, don't assume the results are unassailable. These tests are subject to numerous potential errors and vulnerabilities that an experienced DUI defense attorney can identify and exploit.

Successfully challenging breathalyzer results requires immediate action to preserve evidence, thorough investigation of testing procedures and device maintenance, and often expert scientific testimony. The sooner you begin building your defense, the stronger your position will be.

Contact Attorney Sean Quinlan immediately if you've been charged with DUI in York County. We'll thoroughly investigate every aspect of your breathalyzer test, identify weaknesses in the prosecution's evidence, and build the strongest possible defense to protect your rights, your license, and your future. Your first consultation will help you understand your options and the specific strategies available in your case.