Police officers make mistakes. Some police mistakes could lead to the court dismissing DUI charges. Below are the most common law enforcement errors and omissions that could make a potential drunk driving conviction disappear.

Unlawful DUI Checkpoints or Roadblocks

Pennsylvania has strict guidelines for DUI checkpoints or roadblocks. A traffic stop and subsequent DUI arrest may be dismissed for checkpoints that do not meet the following requirements:

Advance Notice

The police department in charge of the checkpoint must alert the public in advance. This public alert might include road signs, social media updates, and notices in print and digital newspapers.

Department Decision

Individual police officers may not create a DUI checkpoint. The police department’s administration must schedule roadblocks and pursue approval through appropriate channels.

Reasonable Location

Police cannot randomly select a location for a DUI checkpoint. Location and times should be based on a history of previous drunk driving accidents.

Objective Standard

The law enforcement agency must use an objective standard as criteria for a DUI stop. Individual officers cannot create their standards.

Brief Stop

DUI checkpoints are brief stops only. Officers are not allowed to detain motorists longer than necessary.

You May Legally Avoid a DUI Checkpoint Location

Drivers are legally permitted to avoid a DUI checkpoint, provided that they do not commit a moving violation. Police officers cannot stop or chase a car based solely on the driver’s action to avoid a DUI roadblock.

Illegal Search & Seizure

The Constitution protects you from unreasonable searches. Police officers are limited to specific conditions in which they may legally search your vehicle during a DUI stop:

Probable Cause

Probable cause means that an officer reasonably suspects that you are intoxicated or impaired. Certain characteristics are associated with a drunk driver, such as:

  • Hair, breath, clothing, or vehicle interior smells like alcohol.
  • Glassy eyes.
  • Slurred speech.
  • Hostile attitude.

While you cannot prevent an officer from searching your car under probable cause, an unlawful search could lead to a dismissal of a DUI.

Contraband or Evidence in Plain Sight

An officer who sees a liquor bottle from outside the vehicle may search your car. However, police cannot ask you to exit the car and rummage around until they find something.

After an Arrest

After an arrest, the police have the right to search your car or the nearby vicinity. However, there may be errors within the arrest or booking process.


Police can search your car with your consent. Any reputable DUI defense attorney will encourage you to withhold consent for a police search.

Arrest or Booking Errors

Police officers must inform you of the following at the time of your arrest:

  • That you have the right to remain silent
  • The right to ask for legal counsel
  • The charges against you

If an officer fails to read the Miranda rights, refuses to let you call an attorney, or violates any other constitutional right, you might have grounds for dismissal.

DUI Testing Errors

Breathalyzer tests are the most common method to determine if someone is legally intoxicated. In Pennsylvania, you are intoxicated if you have a blood alcohol concentration of 0.08% or higher.

However, breath tests are not always reliable. Several types of errors regarding DUI chemical tests might render a drunk driving charge invalid.

Inadequate Training

Police officers must complete training to administer a DUI test correctly. You may ask for proof that the officer who conducted your test received proper guidance for that breathalyzer device. Errors in administering the test frequently occur.

Improper Calibration or Setting

Any deviation from the correct setting or improper calibration could raise questions about a DUI test result. You may ask for documentation to check that the device meets all calibration, testing, and maintenance requirements.

Improper Chain of Custody

All DUI test results require a precise chain of custody. Blood and urine samples are particularly vulnerable to contamination if officers do not follow the proper guidelines. Chemical tests exposed to temperature extremes could be considered invalid.

Improperly Conducted Field Sobriety Tests

Pennsylvania does not require motorists to comply with field sobriety tests, such as standing on one foot or following an object with your eyes. Some individuals fail these tests due to medical conditions that affect their balance and coordination.

It is possible to dismiss a DUI charge based on a poorly administered field sobriety test. The charges could also be dropped if an individual provides medical documentation that casts doubt on the test’s accuracy (such as proof of a neurological condition).

DUI Report Errors

Police reports with incorrect information or inconsistencies with the officer’s testimony or deposition could result in a dismissal of charges. Misconduct, such as lying on a police report, is also grounds for dismissal.

Failure to Appear in Court

Sometimes the court will dismiss a DUI charge if the arresting officer fails to appear in court. At the very least, an attorney can ask for a continuance to further build your defense.

Talk to a DUI Defense Attorney

Police officers are only human: they make mistakes. Sometimes, these errors can help get a DUI charge dismissed. An experienced DUI defense attorney can evaluate your case and determine if there is potential for dismissal.

If you’re facing DUI charges, get help from the Skinner Law Firm. Call 610-436-1410 or reach out online to schedule a free, no-risk consultation.

Article Author

Michael J. Skinner, the founder of Skinner Law Firm LLC, is a former prosecutor with the Chester County District Attorney’s Office.

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