The core of a Drug Recognition Expert's work is a systematic process designed to be thorough, standardized, and objective. The Drug Evaluation and Classification (DEC) Program provides this framework through its 12-step Drug Influence Evaluation (DIE). This isn't a random checklist; it's a logical progression that moves from general observations to specific clinical evidence. Following these steps in order ensures that every evaluation is comprehensive and legally defensible.

The evaluation begins by ruling out alcohol as the primary cause of impairment and gathering initial context.

Step 1: Breath Alcohol Test First, the subject provides a breath sample to measure their Breath Alcohol Concentration (BrAC). If the BrAC level is high enough to explain the observed impairment, the DRE process might not be necessary. If the BrAC is low or zero, but the impairment is clear, you proceed.

Step 2: Interview of the Arresting Officer Next, you'll interview the arresting officer. You need to know what they saw. What was the subject's driving like? How did they behave during the traffic stop? This information provides crucial context for your own evaluation.

Step 3: Preliminary Examination This is a critical medical rule-out step. You'll ask the subject a series of standard questions about their health and recent food, drug, and alcohol consumption. You're looking for any signs that a medical condition, rather than drugs, could be causing the impairment. This is also where you take the first of three pulse readings to establish a baseline.

With alcohol ruled out and immediate medical issues considered, the evaluation moves to a series of psychophysical and physiological tests. These steps gather the clinical evidence needed to form an opinion.

Notice the three pulse checks are taken at different points in the evaluation: at the beginning (Step 3), during the vital signs check (Step 6), and near the end (Step 9). This systematic approach tracks how the subject's heart rate changes over time, which can be a key indicator of the drug category involved. Some drugs cause an initial spike that later subsides, while others lead to a steady increase or decrease.

The final steps involve synthesizing the collected data and seeking scientific confirmation.

Step 11: Opinion of the Evaluator Based on the totality of the evidence from all previous steps, you will form a professional opinion. You will determine whether the subject is impaired and, if so, which drug category (or categories) is the likely cause. You must be able to articulate the specific evidence that led to your conclusion.

Step 12: Toxicological Examination Finally, you'll request a blood, urine, or saliva sample from the subject. A chemical analysis of this sample is used to confirm or refute your opinion. A positive toxicology result that matches your assessment provides powerful corroborating evidence for legal proceedings.

Let's review the core components of the DRE evaluation.

Now, test your knowledge of the sequence and purpose of the 12 steps.

This structured, 12-step process is the foundation of every Drug Influence Evaluation. Mastering it ensures every case is handled consistently, professionally, and justifiably.