Why Drug Recognition Experts Play a Critical Role in Traffic Stops and Trials

Learn how drug recognition experts affect DUI investigations and court cases, and what drivers need to know about DRE testimony. 

Drug-impaired driving is drawing more attention from law enforcement, especially as states update DUI laws to address cannabis and prescription drugs. Now, when someone gets pulled over, law enforcement may call a drug recognition expert to the scene to determine if a driver is under the influence of more than just alcohol.

A single evaluation based on a drug recognition expert’s observations can carry serious consequences. You could face license suspension, expensive penalties, or even jail time, all based on one officer’s input about drug impairment.

This post breaks down how drug recognition experts operate, what happens during a roadside drug recognition expert (DRE) test, and how their findings can affect you in court. If you want to know what to expect, what your rights are, or how to challenge a drug recognition expert’s report, keep reading.

This informational blog is not to be used as legal advice. Always consult a qualified DUI attorney to assist with any drugged driving charge. If you have immediate questions about a DUI, call a DUI.org specialist at (877) 246-7808.

What Is a Drug Recognition Expert?

A drug recognition expert is a specially trained law enforcement officer who evaluates if drivers are suspected of being impaired by drugs. While many people are familiar with roadside alcohol breathalyzers and field sobriety tests, a drug recognition expert uses a step-by-step protocol to determine whether a driver is under the influence of substances other than alcohol.

The DRE training process includes about 88 to 160 hours of classroom and field training over three distinct phases. The officer is required to pass several exams and supervised evaluations before becoming certified.

Criteria Drug Recognition Experts Use to Evaluate Drivers

A drug recognition expert relies on observable clues and standardized checks. The evaluation includes examining the driver’s pupil size, blood pressure, body temperature, and muscle tone. The expert will also ask about a driver's recent drug use and look for signs of impairment that can’t be explained by alcohol alone. This process is intended to differentiate between drug impairment and other possible causes for a driver’s behavior.

How a Drug Recognition Expert Test Works

The drug recognition expert test follows a standardized 12-step process, beginning at the traffic stop and ending with the collection of a toxicology sample. These steps include a preliminary breath test, interview, a physical exam, eye check, divided attention tasks, and more. Not all drug recognition expert tests are conducted the same way, and the effectiveness of each evaluation can depend on both the officer’s training and the circumstances involved in the stop.

Drug recognition expert tests aim to identify what class of drugs might be affecting the driver, but the process remains subjective, even with established protocols.

Learn more: What’s A DRE | Office of Justice Programs, Drug Recognition Experts (DREs) | IACP

Is a Drug Recognition Test the Same as a Field Sobriety Test?

No, a drug recognition test is not the same as a field sobriety test. 

• Field sobriety tests usually include basic coordination tasks, such as walking in a straight line. 
• Drug recognition expert tests involve medical observations, eye exams, and other steps that a regular officer may not perform. 

Not every traffic stop involves a drug recognition expert, but when an officer suspects substance use, they may call in a certified evaluator to run the whole test.

Can You Decline an Evaluation by a DRE During a Traffic Stop?

You have rights at a DUI stop, but laws about declining an evaluation by a drug recognition expert vary by state. Refusing to participate can lead to additional consequences, including a license suspension or additional charges. Always be aware of your specific state’s rules and consult with a DUI attorney if you are unsure about your options.

Here is a related resource: DUI Drug Charges | Getting a DUI for Drugs | DUI.org

Drug Recognition Experts in Court

After a DUI arrest involving suspected drug use, a drug recognition expert can become a key player in the courtroom. Their observations and testimony can shape the direction and outcome of DUI cases.

DRE Role as an Expert Witness

A drug recognition expert often serves as an expert witness in DUI trials. Their testimony can carry significant weight with judges and juries, as they describe the step-by-step observations and scientific procedures they followed. However, a drug recognition expert’s input is not absolute. The judge or jury may weigh this testimony alongside toxicology reports, dashcam footage, or witness statements.

Weaknesses of Drug Recognition Experts

While drug recognition experts receive advanced training, their evaluations are not flawless. There are well-documented limitations and weaknesses that attorneys and drivers should understand when facing DUI charges based on DRE assessments.

The Role of Subjectivity in Arrests

A drug recognition expert’s evaluation, despite standardized training, involves a degree of subjectivity. Officers rely on observations and interpretations, which means two experts could reach different conclusions about the same driver. This subjectivity opens the door to challenges about whether the arrest was justified or if another explanation is possible.

How Defense Attorneys Challenge Drug Recognition Experts

Defense attorneys frequently examine the credentials, methods, and testimony of a drug recognition expert. They may question whether the officer followed the correct protocol or highlight inconsistencies in the drug recognition expert test. Sometimes, a defense attorney will use a drug testing expert witness to dispute the findings, especially if the arrest led to criminal charges based primarily on DRE testimony.

Rate of Inaccuracy in Drug Recognition Experts

Studies show that drug recognition expert evaluations do not always align with toxicology results. Human factors, medical conditions, or protocol errors can all affect the results. The rate of inaccuracy is a matter of ongoing legal debate and underscores the need for independent toxicological evidence.

Learn more: Drug Evaluation and Classification Program, NHTSA

The Future of Drug Recognition Experts

As drug laws and technology change, the role of the drug recognition expert will continue to evolve. Experts expect new tools, such as reliable THC breathalyzers, to impact how DREs operate in the future. However, the value of human observation and specialized training remains central to drugged driving enforcement.

If you need to know what happens in a DUI case, call DUI.org at (877) 246-7808.

Protect Your Rights by Understanding More About DRE Testimony in DUI Cases

A drug recognition expert’s findings can be pivotal in both traffic stops and courtrooms, but their evaluations are not beyond challenge.

If you have questions about a DUI, connect with a DUI.org specialist at (877) 246-7808. Get the answers you need and take the next step toward protecting your rights.

Frequently Asked Questions Regarding Drug Recognition Experts