How a Lawyer Can Challenge a Drug Recognition Expert’s Testimony

When you are stopped in New York on suspicion of driving under the influence, the 12-step protocol used by a Drug Recognition Expert can have a major impact on what happens next. This process is designed to look thorough, moving from physical checks to observations and even toxicology testing. In reality, it often becomes a central piece of the prosecution’s case. The way a DRE interprets your behavior, your appearance, and even your medical signs can influence how charges are filed and how strong the state believes its case to be.

For you, that means the DRE protocol isn’t just routine; it can shape the evidence brought against you in court. Each step has the potential to add weight to the accusation, even when the officer’s methods or conclusions don’t hold up under closer review. Having the right defense matters.

At The Kugel Law Firm, your case is approached with a clear focus on breaking down every part of the DRE process. A New York DWI attorney can review how the officer handled each step, spot mistakes, and challenge conclusions that go beyond the limits of science or the law. You don’t have to accept the DRE’s version of events as the final word. With the right legal support, you have the chance to protect your rights and fight back against charges that could otherwise shape your future. Contact us today at (212) 372-7218 to schedule a consultation and learn more about how our skilled attorneys can assist you.

What a Drug Recognition Expert Does in DWI Cases

If you were stopped for driving while impaired by drugs in New York, you likely encountered a Drug Recognition Expert (DRE). These police officers are trained to identify individuals impaired by substances other than, or in addition to, alcohol. Their findings form the core evidence the prosecutor will use against you. Knowing exactly what a DRE does, why their opinion is used, and, most importantly, where their authority ends is the first step in building your defense. 

When a police officer suspects impairment not fully explained by an alcohol breath test, a DRE is often called in. The DRE’s job isn’t simply to determine if you took drugs; it is to determine if you are impaired and classify the general category of drug causing that impairment. They follow a standardized, systematic 12-step protocol for this evaluation. This comprehensive process involves detailed clinical observations and testing.

The DRE examination includes:

• A Breath Alcohol Test to rule out alcohol as the sole cause of impairment.
• An Interview with the arresting officer to learn about driving behavior and initial observations.
• Medical Checks, including the measurement of blood pressure, pulse rate, and body temperature.
• Eye Examinations, such as the Horizontal Gaze Nystagmus (HGN), to look for involuntary eye movements.
• Divided Attention Tests (like the One Leg Stand and Walk and Turn) to assess coordination.
• A Dark Room Examination to check pupil size and reaction to light.
• An Assessment of Muscle Tone.
• A final Opinion on whether you are impaired and which of the seven drug categories may be involved.
• Toxicology Sample Collection (blood, urine, or saliva) to confirm drug presence.

Every step of this formal process is scrutinized by your legal team to find procedural mistakes that can weaken the prosecution’s entire case against your DWAI charge.

Why Prosecutors Rely on DRE Testimony in Court

Prosecutors use DRE testimony because it provides a mechanism to connect observed impairment with a specific drug category, even before toxicology results are back. A DRE’s testimony is presented as a crucial link between your physical symptoms, such as poor coordination, dilated pupils, or high pulse, and the prosecution’s claim that a drug caused your impaired driving.

In a New York court, the DRE’s final opinion is offered as opinion evidence. This means the DRE states that, based on their training and the 12-step evaluation, they believe you were impaired by a certain type of drug. This opinion can be highly persuasive. It attempts to give structure and scientific weight to otherwise subjective observations made by the arresting officer at the roadside. They argue that because the DRE followed a standardized, formal procedure, their conclusions are reliable evidence of driving while ability impaired (DWAI-drug). 

Remember that while this testimony sounds strong, it is still an opinion based on observation. Your defense attorney can work to demonstrate why that opinion lacks sufficient foundation under New York law.

The Limits of a DRE’s Authority in New York

It is vital to understand that a DRE is a police officer with specific training, not a medical doctor. Their training does not authorize them to diagnose medical conditions or determine the exact level of drug concentration necessary to cause impairment. This is a critical point for your defense.

The DRE’s authority has several important limits your attorney can challenge:

• A DRE cannot legally compel you to submit to the 12-step evaluation after an arrest; this part of the process is voluntary. However, refusing a chemical test (blood or urine) is a separate matter that can lead to license sanctions under New York’s Implied Consent Law.
• The DRE evaluation procedure must be followed exactly as prescribed by the standardized protocol. Any significant deviation from the 12 steps can create grounds to argue that the entire evaluation is unreliable and should be excluded from evidence.
• The DRE’s training only allows them to classify drug impairment into seven broad categories (like CNS Depressants or Narcotic Analgesics). They cannot determine the specific drug, the dosage you consumed, or the time you ingested it.
• They cannot definitively rule out that your symptoms were caused by medical conditions (like diabetes, head trauma, or stroke) or by legal prescription medications. A lawyer’s job is to introduce these reasonable alternative explanations to refute the DRE’s conclusion.

A strong legal defense will focus on these boundaries, highlighting that the DRE’s training is insufficient to overcome alternative medical or legal explanations for your physical state.

Legal Standards Governing Expert Testimony in New York DWI Cases

The prosecution’s entire case against you for DWAI (Driving While Ability Impaired by Drugs) hinges on the court accepting the DRE’s opinion as reliable evidence. In New York, admitting any kind of testimony that isn’t a simple fact, especially testimony rooted in supposed science, is governed by strict legal rules. These rules can determine what evidence a jury is allowed to hear and consider. Your defense centers on challenging the DRE methodology, arguing that their conclusions should be excluded entirely from your trial.

How New York Courts Admit or Exclude Expert Testimony

New York law recognizes that certain issues in a trial are beyond the knowledge of the typical juror; for these issues, a court allows a person with particular skills or training to offer an opinion. The purpose of this opinion is to help the jury understand complex facts or scientific concepts. However, the court has a duty to ensure that this testimony is not merely misleading conjecture or “junk science.”

For testimony to be admissible, your attorney will argue that the prosecution must demonstrate two things:

• Relevance: The testimony must actually be pertinent to your case and help the jury decide a key fact, such as whether you were impaired.
• Reliability: The underlying methodology or principle the person used to form their opinion must be sound and trustworthy.

The judge will carefully weigh these factors to protect your right to a fair trial. If the DRE’s training or methods are found to be unreliable, that officer’s entire testimony about your alleged impairment may never reach the jury.

The Daubert and Frye Standards in Relation to DRE Evidence

To determine reliability, states generally follow one of two legal precedents: Daubert or Frye. It is critical to know that New York state courts exclusively adhere to the Frye Standard.

The Frye Standard (New York): This test focuses solely on “general acceptance” within the relevant scientific community. Under Frye, a scientific principle or methodology is admissible only if it has gained sufficient standing and recognition among the appropriate peer group. This means your defense doesn’t need to prove the DRE protocol is inherently wrong; it just needs to prove that the scientific community does not generally accept the DRE protocol as a scientifically valid method for determining impairment and classifying seven broad drug categories.

The Daubert Standard (Federal Courts): This standard, used in federal courts and many other states, is different. It asks judges to look at multiple factors, including whether the technique can be tested, whether it has been subject to peer review, and its known rate of error. In New York state courts, these factors are not the primary focus, making the lack of scientific consensus on the DRE protocol a powerful line of attack for your attorney.

Your defense strategy can center on presenting evidence that the DRE process is not generally accepted by medical professionals as a standalone method for reliably determining drug impairment under the strict New York Frye rule. Working with an attorney gives you the edge of a legal professional who knows how the evidentiary standards work and how they can apply to your DWI case.

Top-Rated New York DWI Attorney – Rachel Kugel

The 12-Step DRE Protocol: Pinpointing the Prosecution’s Weaknesses

When you are accused of driving while impaired by drugs (DWAI-Drug) in New York, the prosecution often relies heavily on the 12-step Drug Recognition Expert (DRE) evaluation. However, this standardized protocol is fertile ground for a skilled defense attorney to challenge the officer’s process and opinion. At The Kugel Law Firm, our team systematically investigates the officer’s conclusions to find lapses in oversight, focusing on improper procedure, subjective judgment, and the lack of scientific certainty at every stage of the evaluation.

Step 1 – Breath Alcohol Test

The initial step in the protocol is designed to eliminate alcohol as the primary cause of impairment. This is critical because it justifies the shift to a drug investigation. We aggressively identify errors in the initial breath testing procedures, which can include the officer failing to observe you for the mandatory 15-minute period to confirm no residual mouth alcohol affects the reading, or failing to verify the device’s required calibration records under New York law. 

Even when the reading is low but not zero, we can argue that these alcohol results can overlap with drug symptoms, meaning the combination of a trace amount of alcohol and simple fatigue was responsible for your symptoms, not a non-alcohol drug. The DRE’s subsequent decision to proceed with the full evaluation exposes gaps when officers ignore low or zero BAC levels, suggesting they were already biased toward a drug conclusion.

Step 2 – Interview With the Arresting Officer

Before the DRE even touches you, they review the initial arresting officer’s notes and observations. This intake of second-hand information is a key vulnerability. Your attorney will meticulously review both officers’ reports, highlighting inconsistencies between officers’ reports regarding your initial behavior or appearance. This process demonstrates how reliance on second-hand information weakens testimony because the DRE is building their opinion on a foundation already tainted by bias. 

Furthermore, we can point out bias in the arresting officer’s observations if their reports use emotionally charged language to describe your demeanor, which may have prejudiced the DRE before the evaluation even started.

Step 3 – Preliminary Examination and First Pulse Check

This early step is where the DRE first looks for medical and physical indicators. Since the DRE is not a physician, we immediately question the officer’s grasp of medical symptoms. 

Trembling or rapid pulse could simply be a result of the extreme stress of being arrested, not drug use, which the officer lacks the medical background to differentiate. If you have a documented medical condition, such as chronic anxiety or a history of high blood pressure, your attorney can use medical records to provide alternative explanations that are far more credible than the DRE’s assumption. 

Finally, the reliability of on-the-spot pulse checks is inherently challenged because the reading is taken while you are under duress, rendering it an indicator of anxiety, not necessarily impairment.

Step 4 – Eye Examination (HGN, VGN, and Pupil Size)

The eye examination is foundational to the DRE protocol, yet it is fraught with subjectivity and environmental variables. Your defense can focus on attacking the subjectivity of nystagmus testing. 

We can do this by demonstrating that the officer may have moved the stimulus too quickly or failed to hold it at the required maximum deviation, invalidating the results. If the environment was less than ideal, perhaps the light was inconsistent or reflections were present,  can show how environmental factors affect eye observations, leading to inaccurate pupil size measurements or nystagmus interpretation. 

Where it applies, we can present testimony from a medical professional on non-drug causes of eye movements, such as inner ear conditions or neurological issues, which can mimic the signs of drug impairment identified by the DRE.

Step 5 – Divided Attention Psychophysical Tests

These are the field sobriety tests that require you to perform both a mental and physical task simultaneously. These tests are exceptionally easy to challenge. We demonstrate how stress or fatigue can skew results, as being tired, nervous, or distracted will naturally lead to balance and coordination errors that look like impairment but are not drug-related. Furthermore, we can challenge the officer’s instructions or demonstration of the tests, especially if the video evidence shows they failed to clearly explain the tasks or if the testing surface was uneven. Disabilities or medical conditions can also influence performance; if you have a pre-existing injury, arthritis, or a documented balance issue, your poor performance is easily and legitimately explained.

Step 6 – Vital Signs and Second Pulse Check

The DRE takes your pulse, blood pressure, and temperature again to fit your physiological signs into the drug matrix. Because the officer is not a medical professional, we can question the accuracy of non-medical vital checks and the calibration of the equipment used. We can show how anxiety or health conditions alter pulse and blood pressure; a spike in blood pressure is often a pure stress response to being detained, not an indicator of stimulant use.

If the DRE’s interpretation of these vitals is challenged, witnesses with specific scientific knowledge can refute vital sign interpretations. A medical doctor or toxicologist can explain to the jury that your vitals are consistent with a benign, non-drug-related cause.

Step 7 – Dark Room Examinations of Pupil Size and Reaction

In this step, the DRE measures your pupils in specific light conditions to observe constriction and dilation, trying to pinpoint a specific drug category. This highly scientific-seeming step is undermined by a lack of scientific consensus on pupil testing; the assumed correlations between pupil size and drug categories in the DRE manual are frequently contradicted by established pharmacology. 

Environmental lighting variables, even a small amount of inconsistent ambient light in the dark room, can corrupt the officer’s measurements. If you have any medical history related to your eyes, your attorney will use ophthalmology evidence to challenge conclusions, showing that your pupils are naturally irregular or affected by legal medications.

Step 8 – Examination for Muscle Tone

Here, the DRE physically examines your arms and legs for “flaccid” (limp) or “rigid” (stiff) muscle tone. This step is perhaps the most subjective of the entire evaluation, making it easy to challenge. We expose subjective interpretations of “rigid” or “flaccid” muscles, arguing that what the DRE perceives as drug-induced stiffness could simply be tension from an athletic build, stress, or a momentary reflexive reaction. 

We can also show how fitness, stress, or injury affects muscle tone; a person who just exercised or is shaking from cold could display muscle rigidity that the DRE misattributes to a stimulant. We can undermine reliability with cross-examination on training; we question the officer on their qualifications to assess human physiology and their track record for correctly diagnosing muscle tone.

Step 9 – Check for Injection Sites and Third Pulse Check

The DRE checks your body for injection sites, known as “track marks,” and performs a final pulse check. Your attorney will question the legitimacy of visual “track mark” inspections, as the officer is not qualified to medically distinguish a mosquito bite, a healing bruise, or a scar from a true injection site. 

If a mark is noted, we focus on demonstrating alternative causes for skin marks or bruising. The entire point of the repeated pulse checks is exposed by attacking the redundancy of repeated pulse checks; the DRE often performs these checks until they find a reading that fits their theory of impairment, making the final reading highly suspect.

Step 10 – Suspect’s Statements and Other Observations

This step includes incorporating any statements you made during the evaluation. Your defense should focus on the voluntariness of statements provided without counsel; if you were confused, exhausted, or felt coerced, your statements may not be admissible. 

We can also point out confirmation bias in officer interpretations, arguing that the DRE filters any information you provide (like mentioning an allergy pill) through the lens of their pre-existing belief that you are impaired by drugs. Video evidence can contradict observed behavior; if the DRE claims you were “incoherent,” but the video shows you speaking clearly, the physical evidence of the video speaks louder than the officer’s written opinion.

Step 11 – Opinion of the Evaluator

This is the pivotal moment where the DRE delivers their ultimate, all-encompassing conclusion about the specific drug category responsible for your impairment. This opinion can be powerfully challenged by showing how subjective judgment lacks a scientific basis; the opinion is a summary of subjective tests and observations, not a quantifiable medical diagnosis. 

If a toxicology report is available, comparing the DRE’s opinion with toxicology reports often reveals discrepancies. If the DRE identified a stimulant, but the lab found a depressant, the conclusion is fatally undermined. We can also investigate the officer’s qualifications, questioning the officer about their rate of error and the inherent limitations of the DRE process.

Step 12 – Toxicological Examination

The last step involves collecting a biological sample (blood or urine) for laboratory testing. While the results are scientific, the process is not immune to challenge. A strong defense targets the chain of evidence, highlighting gaps in the chain of custody or testing protocol; if the sample was improperly stored, labeled, or transported, the results should be excluded from evidence in a New York court. 

Furthermore, we can investigate the testing methods themselves, demonstrating false positives and laboratory errors, as common legal medications can sometimes trigger a positive result for an illegal substance. We can highlight discrepancies between lab results and DRE opinion; a toxicology report only confirms the presence of a substance, not the level of impairment at the time of driving. If the DRE saw “severe impairment,” but the lab found only a trace amount of an inactive metabolite, the DRE’s conclusion about your condition is invalid.

Every step of the DRE protocol, from the initial breath test to the final toxicological opinion, presents multiple defense opportunities that require specific legal and scientific knowledge. Addressing these challenges and effectively introducing medical and technical defenses is precisely why partnering with a skilled New York DWI attorney is essential to protecting your rights and challenging the prosecution’s case.

Step	Defense Challenge or Vulnerability
Step 1 – Breath Alcohol Test	Failure to observe mandatory waiting period, calibration issues, residual alcohol, or bias in ignoring low BAC.
Step 2 – Interview With the Arresting Officer	Inconsistencies between reports, biased language, or reliance on second-hand information.
Step 3 – Preliminary Examination and First Pulse Check	Stress or anxiety can mimic drug signs; questionable accuracy under pressure.
Step 4 – Eye Examination (HGN, VGN, Pupil Size)	Subjective interpretation, poor lighting, or medical causes for abnormal eye movements.
Step 5 – Divided Attention Psychophysical Tests	Stress, fatigue, uneven surface, unclear instructions, or medical conditions can affect results.
Step 6 – Vital Signs and Second Pulse Check	Anxiety, medical conditions, or uncalibrated equipment can skew results.
Step 7 – Dark Room Examinations of Pupil Size and Reaction	Lighting inconsistencies, natural variations, or effects of legal medications.
Step 8 – Examination for Muscle Tone	Subjective judgment; muscle tone affected by stress, temperature, or exercise.
Step 9 – Check for Injection Sites and Third Pulse Check	Innocent marks mistaken for injection sites; inconsistent pulse readings.
Step 10 – Suspect’s Statements and Other Observations	Statements may be coerced or misinterpreted; video may contradict report.
Step 11 – Opinion of the Evaluator	Opinion is subjective and may conflict with toxicology results.
Step 12 – Toxicological Examination	Chain of custody issues, lab errors, or false positives can undermine results.

Turning Weaknesses in the DRE Evaluation Into Your Defense

The 12-step protocol can look official and convincing on paper, but it is far from flawless. Every stage of the process can be questioned when the right defense strategy is in place. A DWI attorney from The Kugel Law Firm can challenge the reliability of the officer’s conclusions, expose errors in the evaluation, and present evidence that protects your rights. You don’t have to let a DRE’s testimony dictate the outcome of your case. If you or someone you care about is facing DWI charges in New York, reach out to The Kugel Law Firm today. An experienced New York DWI lawyer is ready to review your case, guide you through your options, and fight for the best possible result in court.