Drug-Related DUI: How Law Enforcement, Prosecutors Prove Impairment

In Pennsylvania, people can be arrested and charged with DUIs when they are under the influence of an intoxicating substance, including illegal or prescription drugs. While most people understand that the legal limit for driving in the state is 0.08% for alcohol, they might not understand how police officers and prosecutors determine impairment when people have drugs in their systems or what the state must show to charge and convict someone for driving while impaired by drugs.

Retaining a Chester County PA DUI lawyer at DiCindio Law might help you understand what to expect while building a strong defense against your charges.

DUIs Involving Drugs and Arrests by Police Officers

Before an officer can stop your car, he or she must first have reasonable suspicion that you have violated a traffic law or a crime. Other than at sobriety checkpoints, police officers are not allowed to randomly pull people over based on a hunch that something might be amiss.
Some of the types of reasons that might form the basis for a valid stop include the following:

  • Weaving
  • Speeding
  • Driving too slowly
  • Drifting between lanes
  • Erratic driving
  • Almost colliding with other cars or objects
  • Non-working headlights or taillights

An officer might develop reasonable suspicion that a driver is intoxicated after stopping the driver for another reason. For example, if an officer pulls you over because your tags are expired, he or she might reasonably suspect that you are under the influence by observing your body movements, appearance, demeanor, and any odors emanating from your breath or vehicle.

If an officer has reasonable suspicion that you are under the influence, he or she will then investigate further to try to develop probable cause to place you under arrest. An officer might look for signs of impairment, including bloodshot eyes, unusual behavior, clumsy motor movements, and slurred speech.

If he or she sees these types of indicators, he or she might ask you to step out of your vehicle to perform some roadside tests. If the officer believes that you are impaired by drugs, he or she will likely call a drug recognition expert or DRE to the scene.

A DRE is an officer who has undergone training to recognize signs of drug impairment. He or she might ask you to perform a number of tests at the roadside when you are suspected to be impaired but submit a negative breath test for alcohol on a portable breath device.

If the DRE decides that you are likely impaired by drugs, you will be placed under arrest and transported to a hospital or the police station for blood testing. Breath tests cannot be used to detect the presence of drugs.

Your attorney can challenge the stop, search, and arrest in your case based on a lack of reasonable suspicion or probable cause. If successful, your case might be dismissed. If the officer did not have probable cause to arrest you, any blood tests might be suppressed.

Police officers also rely on other evidence to support their reasons for arresting people for DUIs involving drugs. These involve the statements motorists have made about using drugs and any drugs that they might find in their cars. If you refuse chemical testing after your arrest, you will face an automatic suspension of your driving privileges and the penalties associated with the highest BAC DUI.

What the Prosecutor Must Prove

After you have been arrested for a DUI involving drugs, the prosecutor will have the task of deciding whether to charge you and prosecute you. This involves showing that the officer followed the procedures and rules for stopping, searching, and arresting you.

The prosecutor will also need to prove that you were under the influence of drugs while you drove, operated, or had actual physical control of a vehicle.

The prosecutor always has the burden of proof. To prove your guilt, he or she will have to present evidence to prove each of the elements of the offense beyond a reasonable doubt.

Typically, prosecutors will rely on the evidence the police officers gathered during their investigations and arrests to prove that you had drugs in your system and were impaired. This can include the police officer’s observations of you, any statements you made, your performance on any roadside tests, and the results of your chemical test.

If you had prescription drugs in your system, you can be charged with a DUI. However, if you had a valid prescription, you can challenge a finding of impairment by arguing that the level of prescription medications did not indicate that you were impaired.

If you had illegal drugs in your system, you will face the penalties of the highest BAC DUI in Pennsylvania. However, your attorney can challenge the blood test by showing problems with how your sample was collected, stored, transported, or analyzed.

Prosecutors will normally call the arresting officers and the DREs to testify against people facing DUIs involving drugs. The analyst who analyzed your sample at the forensic lab will also likely be called to testify. Your attorney can cross-examine each of the witnesses called by the prosecutor and challenge their testimony by relying on reports, videos, lab analysis, or experts.

Contact Our Criminal Defense Law Firm in West Chester, PA

Facing a charge of a DUI involving drugs in Pennsylvania is serious. The penalties that you might face are the most severe penalties for misdemeanor DUI offenses.

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

DiCindio Law, LLC

29 S Walnut St
West Chester, PA 19382
(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.***